With Xcode 9.3 (beta), I'm facing an issue with Xcode tool, while I try to build/run the application (project) for the first time, after Xcode launch/start.
Several times, it prevents project build with the message on status bar:
Waiting for iPhone-X to start
While my simulator is already started and working (There is no any activity, going on, in the simulator).
Here is reference snapshot:
As a temporary solution, I force close Xcode (9.3) and start again.
Is there anyone facing the same issue with Xcode 9.3 beta?
Update: Same issue in Xcode 9.3-Beta 2 also.
Here is How I fixed:
Due to quirks (most likely Simulator bugs) in the Simulator launching on both Xcode 8 and 9, there is no common code to have it launch successfully on both Xcodes. Through experimenting, I have found these to be most reliable:
Xcode 9:
killall Simulator
xcrun simctl boot <device_id>
open `xcode-select -p`/Applications/Simulator.app
Xcode 8:
killall Simulator
xcrun simctl shutdown booted
xcrun instruments -w <device_id>
refer: [iOS 11][Xcode 9] launch, install, start hangs Simulator #209
What (most of the time) works for me, is first launch it on a device. Kill it and then run it on a simulator.
Make sure you don't have the previous Xcode's version of Simulator running when you attempt to run Simulator from the new Xcode, because Xcode will attempt to use that one. (each Xcode bundles it's own Simulator)
Shut down the old Simulator, and try again.
Also, make sure in Xcode > Preferences > Locations > Command Line Tools is pointing to the current Xcode build.
What worked for me : open the simulator device manually (File -> Open Device -> pick the one). Then restart it by going to Device -> restart.
Then try rerunning on xcode.
I've experienced this lots of times especially in beta releases, until I discovered a 'hack' or perhaps a nice way to prevent such issue. But before that, I might add as well this SO link that has a compilation of .dmg Xcode download links. How to download Xcode DMG or XIP file?
TL;DR In order to prevent this kind of issue, just stop debugging or click on STOP button before building/running your application.
Related
I recently installed the beta of Xcode Version 6 in OS X Mavericks, with which comes the iOS simulator for iOS 8. I've managed to successfully run from Xcode 6 beta on a device with iOS 8 Beta, but opening the simulator always get the same error I have tried to change the hardware version of iPhone 4s, iPhone 5, ... in the simulator and still gives the same error: "Unable to boot the iOS Simulator".
I'm working with Xcode 5.1 at the same time in Mavericks, any suggestion to solve this? Is a possible problem for run this simulator in Mavericks because is only for OS X 10.10? Thanks.
After I found some solutions on the web, a combination of procedures worked for me:
Close Xcode and iOS Simulator (and all related applications)
Install (or reinstall) Xcode6-Beta to Applications folder (direct from the .dmg file)
Open Xcode6-Beta and go to Xcode -> Preferences -> Locations -> Command Line Tools and select "Xcode 6.0" (be sure that you've selected the one in Applications folder)
Launch the iOS Simulator and go to iOS Simulator -> Reset Content and Settings...
Close all the applications and restart your mac (I unchecked "Reopen windows...")
Open Xcode6-beta and test the iOS Simulator
Good luck
I also had this problem and found the solution by doing following steps:
Initially i downloaded Xcode 6 library in Documentation section under the path Xcode --> Preferences --> Downloads and restart my xcode but didn't solve my problem.
Downloaded and installed the iOS 7.1 Simulator under the path Xcode --> Preferences --> Downloads.
Restart xcode again and the problem solved.
I am facing same issue again next morning.
Unsetting the DYLD_INSERT_LIBRARIES variable solves my problem:-
Open terminal and type "sudo vi /etc/launchd.conf" command and press Enter
Press I "Insert" mode and change this
"setenv DYLD_INSERT_LIBRARIES /usr/lib/libimckit.dylib"
to this
"unsetenv DYLD_INSERT_LIBRARIES /usr/lib/libimckit.dylib"
and press esc to exit from insert mode.
Save changes by typing ":wq" Press Enter
Reboot your system and problem soloved.
Prior to that I didn't find any iOS version in front of each listed devices
but after installation or by unsetting DYLD_INSERT_LIBRARIES variable I found the same in front of each device.
I solved by removing and re-adding the simulators see screenshots here.
https://stackoverflow.com/a/25387715/1565615
I don't believe your issue is related to running Xcode 6 in Mavericks, as I encountered the same error on OS X 10.10.
After a bit of toying around with XCode and the iOS Simulator, the only fix I found was simply restarting the computer, and the error hasn't appeared since.
Try a reboot and then see if you can get things up and running.
(On a side note, after restarting just XCode (not the OS), I lost the option to run on the simulator at all—the reboot also fixed this problem, if anyone here encounters anything similar).
In Xcode go to the Xcode menu->Open Developer Tool - IOS Simulators. Choose simulator and then go hardware->device->manage device.
If the troubled device shows in the left column, delete it. Then add the device back from the '+' button. If it wasn't there in the first place, simply add it using the '+' button.
I had previously deleted ~/Library/Developer/CoreSimulator/ directory and the only command that worked for me is xcrun simctl erase all. Perhaps you might want to give this a try.
No need to download a new ios version. All you need is to go to About this Mac > Storage > Manage > Delete XCode Cache. And, it works for me
In latest OS version
About this Mac > Storage > Manage > Developer > select Xcode cache > Click delete button
I've faced same issue and solved by below steps:
1) Move xcode6-beta into application folder
2) Restart mac and open xcode6-beta from application folder.
i too had the same issue, but solved by installing the required simulators (Xcode > Preferences> downloads > install simulators)
This happened to me running the simulator on both Xcode 7 and 8 on El Capitan. The only thing that worked was disabling System Integrity Protection (https://apple.stackexchange.com/a/208481/86757).
I tested an awful quantity of solutions and the only one which worked for me was disabling root protection through Recovery Mode. I tested it with XCode 7.3, it's possible that this approach may work for XCode 8.
Reboot and hold the keys cmd + R prior to show the loading view with Apple Logo
When you are on Recovery Mode, go to Menu and choose Terminal
Type csrutil disable
Reboot the machine and run the simulator again.
I am adding this answer as it seems to be slightly different from the others.
Due to working on an older project I needed to download and run Xcode 7.3 and load the project in simulator - this yielded the "Unable to boot the iOS Simulator" error.
I completed all the above suggestions and none of them worked (reset simulator setting, restarted, deleted and reinstalled Xcode, reset the simulator location, restarted again etc)
In the end the issue was that I was trying to load the iPhone 5 (10.0) simulator on Xcode 7.3.
You can see here the Apple release notes for Xcode 7.3
Xcode 7.3 requires a Mac running OS X 10.11 or later.
Xcode 7.3 includes SDKs for iOS 9.3, watchOS 2.2, OS X version 10.11.4, and tvOS
9.2.
As you can see Xcode 7.3 doesn't include an SDK for iOS 10.0
This meant as soon as I loaded the simulator with iPhone 5 (9.3) it worked immediately.
I would therefore recommend when approaching this issue not to get railroaded (as I did) in thinking that something is wrong with the system before checking the basic things.
Note: It is also worth noting that the simulator must be configured to the Xcode version being used. This can be set in
Xcode -> Preferences -> Locations -> Command Line Tools
and also using the command line:
sudo xcode-select --switch /Applications/Xcode_7.3.app/Contents/Developer
*change the Xcode version to the new one you want to use
one of the reasons could be you might deleted /private folder.
you can try with following commands
sudo mkdir /private/tmp
sudo chmod 1777 /private/tmp
Following are the steps for solved above issue:
Search launchd.conf file in your mac
If not found then create from Terminal with help of command
~ user$ sudo touch /etc/launchd.conf
Terminal will ask you machine password
Then Open created file with help of command for EDIT, if terminal give you error as permission failed
~ user$ sudo /Applications/TextEdit.app/Contents/MacOS/TextEdit /etc/launchd.conf
Open file manually from /etc/launchd.conf (Shift+cmd+g) and enter /etc/ (TextEdit software)
In file "DYLD_INSERT_LIBRARIES" flag replace with "ZZ" and save it.
Restart your machine.
Xcode will defiantly works.
This error indicates an error starting up launchd_sim when booting the simulated device. In and of itself, it does not indicate the actual cause. You can look in ~/Library/Logs/CoreSimulator/CoreSimulator.log for more information about the error (including the error reason).
Possible causes:
On OSX 10.9 and earlier, DYLD_INSERT_LIBRARIES could be set by 3rd party applications. On later versions, invalid DYLD_INSERT_LIBRARIES are ignored instead of resulting in an error.
Usage of older simulator runtime DLC with Xcode 7 betas. Newer versions of Xcode ignore these older DLC.
If you need additional help, please provide that additional datum.
Just check your simulator's iOS version. I fought with this error for 2 days and tried everything. Once I run the project on the simulator with iOS version that my Xcode supports, it worked sadly... :/
I quit everything and restarted the Mac. That's all. Its worked like charm!!
I don't know why, but this happened to me when I had Charles Proxy's throttling turned on.
I didn't have to run Xcode again or clean anything. Just disabling the throttling allowed the simulator to work again.
I also clicked on details, but this was all that I got:
Details
Unable to boot the Simulator. Domain: NSPOSIXErrorDomain
Code 60
Failure Reason: launchd failed to respond.
This might be related a known Xcode 11.2 issue:
Third party “endpoint security” software may cause slow simulators, system freezes, or prevent debug processes from running in simulators reliably. This sometimes manifests as debugserver disconnections or simulator applications receiving a SIGKILL signal. (55853555)
Workaround: Uninstall the third party software.
Though I was seeing this error on 11.1. Yet Apple may have just not realized this was an issue on 11.1 as well ¯_(ツ)_/¯
I have solved this issue using following steps:
Xcode -> Preferences -> Location -> Derived Data -> Delete your project folder.
I got this error on OS Catalina, Xcode 11.
I solved this by simply quiting simulator and Xcode, and then start Xcode and run your application.
1. Quit Xcode and Simulator if running.
2. Remove customised settings setup
defaults delete com.apple.Xcode
3. remove configuration folders
rm -rf ~/Library/Application\ Support/Xcode
4. Quit the terminal and run Xcode again.
Resetting the simulators fixed the issue for me. Run the below
Fastlane command to reset all simulators,
fastlane snapshot reset_simulators
Please ensure you have closed Xcode & simulator before running the command.
Fastlane is an Android & iOS deployment automation tool.
I just simply follow the below steps and the issue is resolved...
Go to About This Mac > Storage > Manage > Developer >
Select Xcode cache > Delete the cache
Now try to open the simulator again and it will work... In case if above steps did not work just try to do the same with s
Late answer, but it maybe helpful to someone. I tried all the solutions provided in this and related posts and neither of them worked.
I am using OSX(version 10.10.3) and Xcode 6.2. To fix this issue I followed the following steps :
Delete all xcode and simulator related files using AppCleaner.
Restart Mac.
Open Disk Utility app from applications.
In Disk Utility app; click on button Verify Disk Permission for your Macintosh HD (there will be some warnings displayed; I think /private/tmp is cause of this issue).
In Disk Utility app; click on button Repair Disk Permission for your Macintosh HD.
Re-install Xcode; now it should work.
More info : How to fix Xcode error ‘Unable to boot iOS Simulator’.
This may helpful
Open simulator with 4s
Click on menu- iOS simulator
Click on Reset content and settings...
Force close the simulator and run app.
I'm trying to test one of my apps on ios 10. I have downloaded the Xcode 8 beta which ships with the ios 10.0 Simulator. However, as expected, Xcode 8 is throwing tons of errors on the libraries I'm using [like Alamofire] which is preventing me from building in Xcode 8, which I don't feel I need to worry about right now. I'm just looking for an easy way to run the last stable compiled version (which I can successfully build within Xcode 7 for ios 9.3). I am unable to trigger the ios 10.0 Simulator from my terminal via xcrun as I have used to achieve similar things in the past.
Any guidance would be much appreciated!
EDIT -- Solved
I figured out a way to achieve what I was looking for, for those interested.
In Xcode7 go to Preferences > Locations > and change Command Line Tools to Xcode 8.0
In Terminal, type xcrun simctl list to see the available Simulators (ios 10.0 simulators should be available now).
Copy the UDID of the Simulator you want.
Make sure the normal Simulator app is not running, then run open /Applications/Xcode-beta.app/Contents/Developer/Applications/Simulator.app --args -CurrentDeviceUDID <Copied UDID>
After the desired Simulator is booted, run xcrun simctl install booted <path to project .app file> (the path to the .app file can be found in Xcode on the left pane, under your main project, under the folder "Products" copy the file path from the [project-name].app file located there)
This should install the app onto the desired Simulator. I did encounter some errors the first few times I tried this. I got around them by simply quitting the Simulator.app and trying again (Worked for me on the fourth try).
The iOS 7.1 simulator stopped working some time ago. I always get the dreaded Unable to boot iOS simulator error. The iOS 8.3 simulator works.
I have gone through all the related answers, and have tried all this to no avail:
Deleting Xcode.app and installing it again from the app store.
Deleting all simulator devices and recreating them from Window -> Devices.
Manually deleting the 7.1 simulator runtime from /Library/Developer/CoreSimulator/Profiles/Runtimes and reinstalling through the preferences pane.
Manually deleting all simulator Content and Settings from ~/Library/Developer/CoreSimulator/Devices.
Making sure a DYLD_INSERT_LIBRARIES environment variable is not set.
Making sure the correct Command Line Tools options is set in the preferences pane.
all sprinkled with restarts.
I don't know what else to do, sort of completely reinstalling OS X, which I'd prefer to avoid. This is using Xcode 6.3.2 (6D2105) on Yosemite 10.10.4 (14E36b).
Any ideas?
For people having the "Unable to boot the iOS Simulator" issue while running Xcode 6.x and who've upgraded to OS X 10.11 El Capitan, be warned that there is no effective solution as the iOS 7 simulator is functionally incompatible with El Cap.
See the following Apple Developer forum thread and read the response by jeremyhu:
https://forums.developer.apple.com/thread/5612
"This is a specific incompatibility of the iOS 7.1 libxpc being too old to satisfy the needs of the host's libsystem_stats.dylib."
Same issue for me and fixed it.
Run the following commands in order in Terminal. I'm not sure what's causing it but I have to run it every so often to fix it.
sudo mkdir /private/tmp
sudo chmod 0777 /private/tmp
I was using Xcode 6.0.1 till now and things were fine. Then I upgraded to Xcode 6.1 and tried running my application(which has a deployment target of 7.0) in iPhone 6 simulator. But it shows an error message :
The iOS 8.1 simulator runtime is not available. Download the iOS 8.1 simulator runtime from the Downloads section in Xcode's Preferences
I manually deleted the earlier Xcode (6.0.1) and installed 6.1 from a dmg.
I tried searching across but couldn't find related stuff. Any help would be appreciated.
It is a Mac problem, not an Xcode problem.
Logout the user, shutdown, restart or just reboot Mac. Your Xcode simulator will go back to normal.
For anyone still facing this issue, this command worked for me:
sudo killall -9 com.apple.CoreSimulator.CoreSimulatorService
Rebooting did not help me.
Installing/Reinstalling Simulators worked!!
Look under (XCode Preferences-> Downloads -> Components)
Maintain an accurate list of iOS simulators
When upgrading, you may drag around old simulators no longer available with your current version of Xcode. You can clean these by running this command in Terminal:
xcrun simctl delete unavailable
Quit Xcode first just for good measures. From the documentation:
Delete a device or all unavailable devices.
Rebooting my computer fixed this exact issue for me. Same error was thrown for both iOS7 and iOS8 simulators. I'm on OS X 10.10 and Xcode 6.1.
Just had this problem with Xcode 8 beta 5. I downloaded ios8 and 9 simulators, but was not able to run my app. I simply deleted derived data and rebooted my computer. It worked for me.
I recently installed the beta of Xcode Version 6 in OS X Mavericks, with which comes the iOS simulator for iOS 8. I've managed to successfully run from Xcode 6 beta on a device with iOS 8 Beta, but opening the simulator always get the same error I have tried to change the hardware version of iPhone 4s, iPhone 5, ... in the simulator and still gives the same error: "Unable to boot the iOS Simulator".
I'm working with Xcode 5.1 at the same time in Mavericks, any suggestion to solve this? Is a possible problem for run this simulator in Mavericks because is only for OS X 10.10? Thanks.
After I found some solutions on the web, a combination of procedures worked for me:
Close Xcode and iOS Simulator (and all related applications)
Install (or reinstall) Xcode6-Beta to Applications folder (direct from the .dmg file)
Open Xcode6-Beta and go to Xcode -> Preferences -> Locations -> Command Line Tools and select "Xcode 6.0" (be sure that you've selected the one in Applications folder)
Launch the iOS Simulator and go to iOS Simulator -> Reset Content and Settings...
Close all the applications and restart your mac (I unchecked "Reopen windows...")
Open Xcode6-beta and test the iOS Simulator
Good luck
I also had this problem and found the solution by doing following steps:
Initially i downloaded Xcode 6 library in Documentation section under the path Xcode --> Preferences --> Downloads and restart my xcode but didn't solve my problem.
Downloaded and installed the iOS 7.1 Simulator under the path Xcode --> Preferences --> Downloads.
Restart xcode again and the problem solved.
I am facing same issue again next morning.
Unsetting the DYLD_INSERT_LIBRARIES variable solves my problem:-
Open terminal and type "sudo vi /etc/launchd.conf" command and press Enter
Press I "Insert" mode and change this
"setenv DYLD_INSERT_LIBRARIES /usr/lib/libimckit.dylib"
to this
"unsetenv DYLD_INSERT_LIBRARIES /usr/lib/libimckit.dylib"
and press esc to exit from insert mode.
Save changes by typing ":wq" Press Enter
Reboot your system and problem soloved.
Prior to that I didn't find any iOS version in front of each listed devices
but after installation or by unsetting DYLD_INSERT_LIBRARIES variable I found the same in front of each device.
I solved by removing and re-adding the simulators see screenshots here.
https://stackoverflow.com/a/25387715/1565615
I don't believe your issue is related to running Xcode 6 in Mavericks, as I encountered the same error on OS X 10.10.
After a bit of toying around with XCode and the iOS Simulator, the only fix I found was simply restarting the computer, and the error hasn't appeared since.
Try a reboot and then see if you can get things up and running.
(On a side note, after restarting just XCode (not the OS), I lost the option to run on the simulator at all—the reboot also fixed this problem, if anyone here encounters anything similar).
In Xcode go to the Xcode menu->Open Developer Tool - IOS Simulators. Choose simulator and then go hardware->device->manage device.
If the troubled device shows in the left column, delete it. Then add the device back from the '+' button. If it wasn't there in the first place, simply add it using the '+' button.
I had previously deleted ~/Library/Developer/CoreSimulator/ directory and the only command that worked for me is xcrun simctl erase all. Perhaps you might want to give this a try.
No need to download a new ios version. All you need is to go to About this Mac > Storage > Manage > Delete XCode Cache. And, it works for me
In latest OS version
About this Mac > Storage > Manage > Developer > select Xcode cache > Click delete button
I've faced same issue and solved by below steps:
1) Move xcode6-beta into application folder
2) Restart mac and open xcode6-beta from application folder.
i too had the same issue, but solved by installing the required simulators (Xcode > Preferences> downloads > install simulators)
This happened to me running the simulator on both Xcode 7 and 8 on El Capitan. The only thing that worked was disabling System Integrity Protection (https://apple.stackexchange.com/a/208481/86757).
I tested an awful quantity of solutions and the only one which worked for me was disabling root protection through Recovery Mode. I tested it with XCode 7.3, it's possible that this approach may work for XCode 8.
Reboot and hold the keys cmd + R prior to show the loading view with Apple Logo
When you are on Recovery Mode, go to Menu and choose Terminal
Type csrutil disable
Reboot the machine and run the simulator again.
I am adding this answer as it seems to be slightly different from the others.
Due to working on an older project I needed to download and run Xcode 7.3 and load the project in simulator - this yielded the "Unable to boot the iOS Simulator" error.
I completed all the above suggestions and none of them worked (reset simulator setting, restarted, deleted and reinstalled Xcode, reset the simulator location, restarted again etc)
In the end the issue was that I was trying to load the iPhone 5 (10.0) simulator on Xcode 7.3.
You can see here the Apple release notes for Xcode 7.3
Xcode 7.3 requires a Mac running OS X 10.11 or later.
Xcode 7.3 includes SDKs for iOS 9.3, watchOS 2.2, OS X version 10.11.4, and tvOS
9.2.
As you can see Xcode 7.3 doesn't include an SDK for iOS 10.0
This meant as soon as I loaded the simulator with iPhone 5 (9.3) it worked immediately.
I would therefore recommend when approaching this issue not to get railroaded (as I did) in thinking that something is wrong with the system before checking the basic things.
Note: It is also worth noting that the simulator must be configured to the Xcode version being used. This can be set in
Xcode -> Preferences -> Locations -> Command Line Tools
and also using the command line:
sudo xcode-select --switch /Applications/Xcode_7.3.app/Contents/Developer
*change the Xcode version to the new one you want to use
one of the reasons could be you might deleted /private folder.
you can try with following commands
sudo mkdir /private/tmp
sudo chmod 1777 /private/tmp
Following are the steps for solved above issue:
Search launchd.conf file in your mac
If not found then create from Terminal with help of command
~ user$ sudo touch /etc/launchd.conf
Terminal will ask you machine password
Then Open created file with help of command for EDIT, if terminal give you error as permission failed
~ user$ sudo /Applications/TextEdit.app/Contents/MacOS/TextEdit /etc/launchd.conf
Open file manually from /etc/launchd.conf (Shift+cmd+g) and enter /etc/ (TextEdit software)
In file "DYLD_INSERT_LIBRARIES" flag replace with "ZZ" and save it.
Restart your machine.
Xcode will defiantly works.
This error indicates an error starting up launchd_sim when booting the simulated device. In and of itself, it does not indicate the actual cause. You can look in ~/Library/Logs/CoreSimulator/CoreSimulator.log for more information about the error (including the error reason).
Possible causes:
On OSX 10.9 and earlier, DYLD_INSERT_LIBRARIES could be set by 3rd party applications. On later versions, invalid DYLD_INSERT_LIBRARIES are ignored instead of resulting in an error.
Usage of older simulator runtime DLC with Xcode 7 betas. Newer versions of Xcode ignore these older DLC.
If you need additional help, please provide that additional datum.
Just check your simulator's iOS version. I fought with this error for 2 days and tried everything. Once I run the project on the simulator with iOS version that my Xcode supports, it worked sadly... :/
I quit everything and restarted the Mac. That's all. Its worked like charm!!
I don't know why, but this happened to me when I had Charles Proxy's throttling turned on.
I didn't have to run Xcode again or clean anything. Just disabling the throttling allowed the simulator to work again.
I also clicked on details, but this was all that I got:
Details
Unable to boot the Simulator. Domain: NSPOSIXErrorDomain
Code 60
Failure Reason: launchd failed to respond.
This might be related a known Xcode 11.2 issue:
Third party “endpoint security” software may cause slow simulators, system freezes, or prevent debug processes from running in simulators reliably. This sometimes manifests as debugserver disconnections or simulator applications receiving a SIGKILL signal. (55853555)
Workaround: Uninstall the third party software.
Though I was seeing this error on 11.1. Yet Apple may have just not realized this was an issue on 11.1 as well ¯_(ツ)_/¯
I have solved this issue using following steps:
Xcode -> Preferences -> Location -> Derived Data -> Delete your project folder.
I got this error on OS Catalina, Xcode 11.
I solved this by simply quiting simulator and Xcode, and then start Xcode and run your application.
1. Quit Xcode and Simulator if running.
2. Remove customised settings setup
defaults delete com.apple.Xcode
3. remove configuration folders
rm -rf ~/Library/Application\ Support/Xcode
4. Quit the terminal and run Xcode again.
Resetting the simulators fixed the issue for me. Run the below
Fastlane command to reset all simulators,
fastlane snapshot reset_simulators
Please ensure you have closed Xcode & simulator before running the command.
Fastlane is an Android & iOS deployment automation tool.
I just simply follow the below steps and the issue is resolved...
Go to About This Mac > Storage > Manage > Developer >
Select Xcode cache > Delete the cache
Now try to open the simulator again and it will work... In case if above steps did not work just try to do the same with s
Late answer, but it maybe helpful to someone. I tried all the solutions provided in this and related posts and neither of them worked.
I am using OSX(version 10.10.3) and Xcode 6.2. To fix this issue I followed the following steps :
Delete all xcode and simulator related files using AppCleaner.
Restart Mac.
Open Disk Utility app from applications.
In Disk Utility app; click on button Verify Disk Permission for your Macintosh HD (there will be some warnings displayed; I think /private/tmp is cause of this issue).
In Disk Utility app; click on button Repair Disk Permission for your Macintosh HD.
Re-install Xcode; now it should work.
More info : How to fix Xcode error ‘Unable to boot iOS Simulator’.
This may helpful
Open simulator with 4s
Click on menu- iOS simulator
Click on Reset content and settings...
Force close the simulator and run app.