Unable to boot the iOS Simulator after deleting /private/tmp - ios

Question

This week I cannot boot my Simulator, I tried several solutions from some articles, but it doesn't work. My MacOS version is OS X 10.10.5 (14F27), and my Simulator is iOS 8.4.
I grabbed the log from ~/Library/Logs/CoreSimulator/CoreSimulator.log
Aug 27 11:29:14 LL-MBP.local CoreSimulatorService[8316] : Could
not register service com.apple.SystemConfiguration.PPPController:
launch_sim_register_endpoint: 0xfffffecc Aug 27 11:29:14 LL-MBP.local
CoreSimulatorService[8316] : Could not register service
com.apple.audio.audiohald: launch_sim_register_endpoint: 0x44e Aug 27
11:29:14 LL-MBP.local CoreSimulatorService[8316] : Could not
register service
com.apple.coreservices.lsuseractivity.simulatorsupport:
launch_sim_register_endpoint: 0x44e Aug 27 11:29:14 LL-MBP.local
CoreSimulatorService[8316] : Could not register service
com.apple.FSEvents: launch_sim_register_endpoint: 0x44e Aug 27
11:29:14 LL-MBP.local CoreSimulatorService[8316] : Could not
register service com.apple.SystemConfiguration.configd:
launch_sim_register_endpoint: 0x44e Aug 27 11:29:14 LL-MBP.local
CoreSimulatorService[8316] : Could not register service
IndigoHIDRegistrationPort: launch_sim_register_endpoint: 0x44e Aug 27
11:29:14 LL-MBP.local CoreSimulatorService[8316] : Could not
register service PurpleFBTVOutServer: launch_sim_register_endpoint:
0x44e Aug 27 11:29:14 LL-MBP.local CoreSimulatorService[8316] :
Could not register service PurpleFBServer:
launch_sim_register_endpoint: 0x44e Aug 27 11:29:14 LL-MBP.local
CoreSimulatorService[8316] : Error Domain=NSPOSIXErrorDomain
Code=60 "Unable to boot the iOS Simulator." UserInfo=0x7fbb204683f0
{NSLocalizedDescription=Unable to boot the iOS Simulator.,
NSLocalizedFailureReason=launchd failed to respond.} Aug 27 11:29:14
LL-MBP.local CoreSimulatorService[8316] : Error
Domain=NSPOSIXErrorDomain Code=60 "Unable to boot the iOS Simulator."
UserInfo=0x7fbb204683f0 {NSLocalizedDescription=Unable to boot the iOS
Simulator., NSLocalizedFailureReason=launchd failed to respond.} Aug
27 11:29:14 LL-MBP.local CoreSimulatorService[8316] : Error
Domain=com.apple.CoreSimulator.SimError Code=146 "Unable to lookup in
current state: Shutdown" UserInfo=0x7fbb20808710
{NSLocalizedDescription=Unable to lookup in current state: Shutdown}
Aug 27 11:29:14 LL-MBP.local CoreSimulatorService[8316] : Error
looking up host support port Aug 27 11:29:14 LL-MBP.local
CoreSimulatorService[8316] : Error
Domain=com.apple.CoreSimulator.SimError Code=146 "Invalid device
state" UserInfo=0x7fbb2083b420 {NSLocalizedDescription=Invalid device
state} Aug 27 11:29:14 LL-MBP.local CoreSimulatorService[8316]
: Error Domain=com.apple.CoreSimulator.SimError Code=146
"Unable to lookup in current state: Shutdown" UserInfo=0x7fbb2080c350
{NSLocalizedDescription=Unable to lookup in current state: Shutdown}
Aug 27 11:29:14 LL-MBP.local CoreSimulatorService[8316] : Error
Domain=com.apple.CoreSimulator.SimError Code=146 "Unable to lookup in
current state: Shutdown" UserInfo=0x7fbb2080c350
{NSLocalizedDescription=Unable to lookup in current state: Shutdown}
Aug 27 11:29:14 LL-MBP.local com.apple.iphonesimulator[8330] :
Error Domain=NSPOSIXErrorDomain Code=60 "Unable to boot the iOS
Simulator." UserInfo=0x7fda2a9020f0 {NSLocalizedDescription=Unable to
boot the iOS Simulator., NSLocalizedFailureReason=launchd failed to
respond.} Aug 27 11:29:14 LL-MBP.local CoreSimulatorService[8316]
: Error Domain=com.apple.CoreSimulator.SimError Code=146
"Unable to lookup in current state: Shutdown" UserInfo=0x7fbb20b0f850
{NSLocalizedDescription=Unable to lookup in current state: Shutdown}
Aug 27 11:29:14 LL-MBP.local CoreSimulatorService[8316] : Error
looking up host support port Aug 27 11:29:14 LL-MBP.local
CoreSimulatorService[8316] : Error
Domain=com.apple.CoreSimulator.SimError Code=146 "Invalid device
state" UserInfo=0x7fbb20b00e20 {NSLocalizedDescription=Invalid device
state}
Does someone have any idea about this?
I will appreciate it!
Finally I fixed this issue with #Jeremy Huddleston Sequoia 's help. At the beginning, I tried lots of solutions online, including remove /private/tmp folder. so that caused no matter how many times I clean reinstall simulator, it doesn't work. so be careful about this

Answer 1

Those errors indicate that launchd_sim is not loaded or not running, and the watchdog fired to notify you of the failure.
If you disable AMFI in OS X 10.10.5, the Simulator runtime will be unusable, and it can manifest like this.
However, in your case, launchd_sim is crashing on launch. The crash log indicates that it is encountering an error when trying to create its state directory in /private/tmp.
This can happen you deleted /private/tmp (or incorrectly recreated it). To create /private/tmp do:
sudo mkdir /private/tmp
sudo chmod 1777 /private/tmp