IISExpress does not start from Visual Studio 2015
Solution 1
Resolution: First I found that opening the very same project in VS 2012 works, it starts IISExpress just fine. So what's different? It's the .vs folder in the projects root and here especially the file .suo where all the user settings specific for Visual Studio 2015 reside.
Delete the folder .vs if you copy a project from another user/machine. Then open the project. It will create a new settings store on the fly. The project will run just as before and IISExpress works as expected.
If you can't see this folder - it's hidden. So make hidden files visible before this step.
Elder projects and elder VS versions does not have the .vs folder and hence no need to delete it.
Solution 2
I just want to share my experience. In my case, I had VS 2015 and VS 2017 installed on my post. I uninstalled VS 2017 and it caused this problem.
this post worked in my case:
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Delete the
\Documents\IISExpress
folder using the following console command:rmdir /s /q "%userprofile%\Documents\IISExpress"
Delete the
applicationhost.config
the file which is placed within the\.vs\Config\
folder in your Visual Studio project root folder.Close Visual Studio and re-start it with Administrative privileges
(right-click > Run as Administrator)
.Change the project’s website random URL: within Visual Studio, right-click to the project node in Solution Explorer, then select Properties; navigate through the Web panel, then change the number in the Project Url textbox value.
Add the
_CSRUN_DISABLE_WORKAROUNDS
Environment System variable with the value of1
(As it is shown on the image on the link.) (I didn't do this step on my post, it worked by doing the first 4 steps).
https://www.ryadel.com/en/unable-launch-iis-express-web-server-error-visual-studio-2015-fix/
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Joerg Krause
I'm a developer, consultant, speaker, and author specialized in ASP.NET Core, EF Core, .NET, Angular/React, TypeScript/ECMAScript, HTML/CSS and all related web technologies. Additionally, I can offer consulting for cloud services, cloud native development, and cloud architectures especially with Azure. I can create Alexa skills on AWS, too. I know how to work with technologies such as Docker. I'm fluent on both, Linux and Windows. I'm available internationally for contract work. I'm especially looking for Azure projects suitable for a real full stack pro (.NET Core or NodeJs).
Updated on February 10, 2020Comments
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Joerg Krause about 4 years
There are several questions here why IISExpress does not launch. The answers I found did not help. But I found the answer myself. This post may help others resolve the issue.
Behavior: You open a web project you copied from somebody else in Visual Studio 2015. You cannot select Browsers and when you start using F5 you get a message that says
Unable to launch the IIS Express Web server.
There is no indication why. Deleting applicationHost.config does not help, restarting / reinstalling etc. does not help either. Admin mode doesn't matter and a new project an the target machine works as expected.
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Michael Freidgeim almost 3 yearsDoes this answer your question? Unable to launch the IIS Express Web server
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Jean-Marie over 7 yearsAnd before removing the .vs close the VS solution
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Chris about 7 yearsIf using VS2015 and a .net Core project, also delete launchSettings.json out of /Properties
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arpan desai about 7 yearswe have copied project from another user/machine. Deleting .vs folder and reopening project works fine for us.
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Cliff Cawley almost 7 yearsI had the same problem with VS 2017 where IIS would launch but my project wasn't added and the page wouldn't load. Performing the above and deleted the .vs folder fix this for me and I can finally launch my project :)
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Lex Li over 5 yearsIf this is the "resolution", accept your own answer and close the thread.