I have a blazor webassembly app that is working fine and it is split in webassembly talking to a web api version all .Net Code
I use VS community Edition 2019 and suddenly after many modifications to my code I noticed that I am not able to debug and see any variable content(unable to Evaluate) at any break points anywhere in my web assembly app. I tried with an old version of my code which I know it was working then and same issue, so it is not the code.
I tried upgrading VS to 16.11.75.64347 ( from 16.6 something) without success and even uninstall & reinstall VS with no success.
The only new thing on my station was a windows update this week.
Is someone had something similar happening this week?
ps: What is weird is that I do not not have this problem in my web API solution portion just the webassembly solution.
I think I've been badluck to find many not working thread but finally it was simply to close VS . delete the .vs directory tehn relod the solution and it was OK. It is weird though that many old version of my code that never had this issue had the same problem. It was impossible to have all those .vs not working although I had not touched them in weeks. Anyway it is now working.
I just created a new web application (MVC 5.2.3) in Visual Studio 2015, and I regularly get errors like this on the HtmlHelpers:
I'm using .NET 4.6 (the default project was set to 4.5.2 originally, however I still had this issue with that default setting). I've looked at a bunch of similar questions on this site, and yet I haven't found a solution that consistently works. Any advice?
This sounds like a corrupted MEF cache to me. Different user, different MEF cache.
The PM of Razor Editing, Mads Kristensen, wrote an extension to make clearing the MEF cache simple. Try this: Clear MEF Component Cache.
You'll just have to restart VS after clearing; rebuilding the cache takes seconds, not minutes.
Please let us know if this solves the problem for you.
UPDATE
I'm certain this is a Visual Studio bug with no obvious solution. I've encountered a number of people who have the same exact issue. I have submitted a bug ticket with Microsoft here:
http://connect.microsoft.com/VisualStudio/feedback/details/778864/vs2012-is-spawning-two-iisexpress-processes-when-attempting-to-debug
If you are having the same issue as described below, please go vote up the bug ticket so that it gets more attention.
Whenever I attempt to debug an MVC3 (or MVC4) application in Visual Studio 2012 configured to run on IIS express (version 8), I get the following error:
Here's the kicker: IIS Express is starting, even though Visual Studio doesn't think so and the debugger fails to attach. The IIS Express tray opens and I can clearly see all configured websites are started:
Oddly enough, the IIS Express System Tray reports that there were some errors when running IIS Express. Here's what it says:
This is a serious WTF. It's reporting that 8080 is being used by an IIS Express Process - the one that was just started by Visual Studio. So, Visual Studio is attempting to launch IIS twice, and when it predictably fails the second time, the debugger bails. I should note that before launching the debug configuration in Visual Studio, I made absolutely sure no IIS Express processes were already running. I used Process Monitor to verify that Visual Studio is in fact attempting to launch IIS Express twice:
Notice in the screen shot above you can clearly see websites running on IIS Express PID 4732. PID 4924 is the second failed attempt at launching IIS Express.
This issue was initially occurring on a Windows 7 installation. I reformatted completely, installed a fresh copy of VS2012, and got the same issue. I went a step further and reformatted, installed Windows 8 and a fresh copy of VS2012, and the issue persists.
I have created brand new blank MVC3 and MVC4 projects. Nothing fixes it.
I'm tearing out my hair here. Any help would be greatly appreciated.
w.Brian, I have followed this post since it's start and have had the exact same problem for quite a while now and I have just discovered what is causing the issue for me. I have been able to reproduce and fix the error for myself with this:
The reason VS2012 is starting iis express twice is related to being attached to a domain and being logged into a domain account. Once I logged into a completely local admin account I was able to launch and debug an MVC4 application without any issues. This is using Windows 8 Pro, VS2012 Update 1, attached to my domain, and no other software/extensions/configuration. Completely clean installation.
Hi maybe this solutions could help you.
Manage RuntimeVersion=”4.0″ to “4.0.30319″
Example:
<applicationPools>
<add name=”Clr4IntegratedAppPool” managedRuntimeVersion=”v4.0.30319″ managedPipelineMode=”Integrated” CLRConfigFile=”%IIS_USER_HOME%\config\aspnet.config” autoStart=”true” /><br/><br/>
reference:Issue: Visual Studio 2012 > “Unable to launch the IIS Express Web Server”
Use Process Monitor to solve the issue
reference: Debugging the “Unable to launch the IIS Express Web server.” error from Visual Studio 2012.
Try switching to the visual studio built in web host and run it. After you run it once you should be able to switch back to iis express
reference: from the forum Unable to launch the IIS Express Web server
try re-installing Visual Studio 2010 SP1, which contains iis-express.
disable the logging module by modifying the applicationhost.config, which is located in the %userprofile%\documents\IISexpress\config directory. To do so you will need to comment out a couple lines in the file.
Under the / element, comment out the line
<add name="HttpLoggingModule" image="%IIS_BIN%\loghttp.dll" />
Under the // element, comment out the line
<add name="HttpLoggingModule" lockItem="true" />
After saving your changes try restarting iis express.
reference: from stackoverflow forum: Unable to launch the IIS Express Web server
Right click you MVC project /*all of them one by one*/
go to properties
go to web tab
you must be having having checked "Use local IIS webserver" radio box
in the textbox below it make sure no to projects have the same port which in your case is 8080
Have a look at the answer here:
http://forums.asp.net/t/1953087.aspx?VS+2013+Unable+to+launch+the+IIS+Express+Web+Server
It was strange behavior on a Windows 8 machine when 'bg' was part of the username
I might be a little late to the party - here's my two pennies:
a) http://saintgimp.org/2012/05/03/fixing-the-error-unable-to-launch-the-iis-express-web-server-failed-to-register-url-access-is-denied/
b) http://abhijitjana.net/2010/07/20/unable-to-start-web-site-on-iis-process-can-not-access-the-file-because-its-being-used-by-another-process-how-to-resolve/
Synopsis: There is a URL reservation for the current port (usually Skype)
Just in case, do you have 127.0.0.1 localhost defined in folder/system32/drivers/stc/hosts ? Otherwize, you can check here, this might just be the key.
Cheers
I had the same issue on Windows 8 and Windows 8.1 using my domain account. In my case changing the Documents folder path (Right click on the Documents folder -> Properties -> Location) from C:\Users\username\Documents to D:\Documents helped
This week, I experienced this identical issue: IIS Express starts, but VS complains it couldn't start IIS Express and debugging fails.
I finally resolved the issue by applying the June 2014 hot-fix to IIS Express:
http://www.microsoft.com/en-us/download/confirmation.aspx?id=43380
We (my IT support and I) found this hotfix after stumbling over and following a very unlikely problem. Apparently, MS verified a bug in IISExpress 8.0 which results in it misbehaving if any part of the application name contains the letter combination "bg" (my username begins with bg):
https://connect.microsoft.com/VisualStudio/feedback/details/848945/visual-studio-2012-iis-express-fails-to-start-if-application-name-contains-bg
Note: VS 2013 Update 4 already contains this fix, which may be why some people had success simply by updating to VS 2013.
Some other links we found concerning the issue (you may have to skim a bit to find the topic):
http://forums.asp.net/t/1953087.aspx?VS+2013+Unable+to+launch+the+IIS+Express+Web+Server
https://connect.microsoft.com/VisualStudio/feedback/details/865116/process-with-an-id-of-id-is-not-running
What worked in my situation was to unload the project, then to edit the csproj file. I removed all sections regarding IIS and IISEXPRESS. Then I reloaded the project and chose USE IIS EXPRESS from the project properties all over again. It then worked.
I ran into an identical issue today (IISExpress trying to start twice and failing when hitting Debug in Visual Studio) while helping another developer with a web forms site. After trying several solutions, we found that we could resolve the problem by:
Creating a new, empty Visual Studio solution
Adding an "Existing Website" pointing to a new, empty folder
Copying the contents of the existing (non-working) website into the new folder we created
Simply removing and re-adding the website to the original solution did not work, nor did creating a new solution and adding back the existing site. I can start IISExpress from the command line just fine.
After doing a before-and-after comparison of the .SLN files I believe that is where the problem lies. Since I had found a workaround I didn't spend a lot of extra time on it. Obviously recreating the entire solution from scratch may not be an option for larger projects (ours was a very small one) but hopefully this at least points in the right direction.
There are two instances of the site FrontEnd running of course, but notice that one instance is HTTP and the other HTTPS.
It's possible to get two instances when SSL Enabled is set to True in the web site properties but the Project Url on the Web tab is set to an HTTP address.
Make them both HTTP (or HTTPS) and that might fix it.
I have been trying to get my feet wet with MVC by building a simple CRUD web application linked to a SQL 2008 database. Everything works great when I run the project from within VS, but I have run into nothing but failure after failure trying to get the application to publish successfully using either IIS 6, or 7.
I have googled my fingers to the bone trying various fixes and methods for publishing, but so far have just been running into wall after wall. I feel like there must be something basic I am overlooking to get this going, but I am stumped.
I was hoping that someone with more experience working in this environment might be able to suggest some rookie mistakes I could be making, or any tips for publishing an MVC web app for the first time.
Thanks in advance,
Patrick Sean Henderson
We really need more information but making some assumptions here are things to verify:
Assumptions:
IIS 7.x
Proper .NET version installed
VS2010 & NuGet
File System Based Deployment
Suggestions:
Make sure you include the deployable assemblies required.
Right Click MVC project in VS
Select "Include Deployable Assemblies"
Check off the required assemblies
I'd have more with more background details
Post an update when you can!
Brent
I started out this morning working with my ASP.NET MVC project like normal and everything worked. I added a new class and some functions and it still worked. Then, all of a sudden, while I was working with a javascript file, I started getting these not defined errors on the MVC classes/functions. There are 118 of them in the project and I'm not sure how to fix them.
I've tried restarting Visual Studio and rebooting the computer. I've also tried loading another MVC project to see if the framework might be hosed, and it works fine. I've checked the references and the ASP.NET MVC 1.0 RC2 dll is there.
Has anyone else ran into this problem?
Please help!
I figured it out. I had added a new Master page to the project, but when did so, I had chosen a regular Master Page not the MVC Master Page. What threw me was that I was able to build the program a couple times and run it after I had done this without seeing any errors.