无法在Web服务器上启动调试。 操作超时

Question

I had this problem with all my ASP.NET websites, I'm on Windows 10, and my IIS application pools stopped working. I have found many and more possible resolutions to this problem while googling, but none of them was working for me. That was not an account problem, or a glich in temp files, not even a bug in Visual Studio that needed to reinitialize the project.

This problem has occured after an update (to be exact, the 1607'th), that amongs other networking things, has reinitialized some of my components, like Microsoft .NET Core tooling preview 2 . I have repaired it, it has worked. Only once.

Any ideas?

Answer 1

So instead of doing like me and loose your time to know why it breaks, simply do it the hard way, with no compromises:

• Go to add / remove windows functionality
• Remove all that corresponds to ASP.NET (in IIS too)
• Restart
• Reinstall all that you have uninstalled earlier
• Restart again. That should fix it.

Oh, you will probably get the error that it cannot download from windows update (error code 0x800F081F). That is .NET 3.5. you can safely install it from offline sources or, if you have Windows installation media, go to powershell in admin mode and type:

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:DRIVE_OF_YOUR_WINDOWS_DISK:\sources\sxs

replace "DRIVE_OF_YOUR_WINDOWS_DISK", with the correct one.

Hope this will help.

Answer 2

I had the same issue and I fixed it by doing a DNS flush: ipconfig/flushdns in command prompt. I was using localhost to test my applications and somehow the IP changed but the reference was still there for them so I just did a DNS flush to update all IPs.

You can also reboot your computer. Turning it off and back on again is usually the quick fix to all IT problems.

Answer 3

Running the iisreset command fixed this issue for me, however in my situation it was only a temporary fix.

In my situation the error kept recurring while stepping through code that was making localhost API calls to other endpoints. After running iisreset the application would function normally for a short amount of time before the localhost API calls would begin timing out. If the debugging session was then ended, and restarted, the "Unable to start debugging on the web server. The operation timed out." error would then be thrown.

What appeared to end up being the root cause of the issue, is that there was a web page (as part of the UI) that was polling another API on regular intervals. If the application was in break mode for a long enough period of time (could range from seconds, to minutes, or longer depending on the polling frequency), without actively stepping through any new lines of code, IIS would become bottlenecked by the polling and would cause timeout errors in the "non-polling" API calls that were part of the program. So, by simply preventing the polling from occurring (ie., closing out / backing out of the webpage doing the polling) this issue went away; however the larger takeaway, is to also examine the IIS traffic to see if you have a traffic bottleneck, possibly caused by a debugging session.