"An operation is not legal in the current state" error when trying to launch ASP.NET project in VS2013?

Question

I have an ASP.NET web site created with WebMatrix 3. I do have the option in VS2013 checked to use the 64-bit version of IIS Express since I am running on 64-bit Windows 8.1. When I try to launch the project I get the error "An operation is not legal in the current state". Does anybody know how to fix this?

did you ever figure this out – johnny 5 Mar 10 '17 at 03:58 — johnny 5, Mar 10 '17 at 03:58

score 3 · Answer 1 · answered May 03 '17 at 08:38

I got this same error "An operation is not legal in the current state" when running a project on Google Chrome, Stopping the project then closing all chrome instances fixed the problem.

I think it's related to visual studio not being able to attach to chrome instance for debugging.

score 3 · Answer 2 · edited Mar 15 '18 at 15:43

3

Closing Chrome and restarting IIS (e.g. in IIS Manager) should solve the issue. It helped in my case.

edited Mar 15 '18 at 15:43

Yusubov

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answered Mar 01 '18 at 17:34

kenorb

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score 0 · Answer 3 · answered Mar 15 '18 at 15:46

0

Just had the same issue on VS (Visual Studio) 2017 this morning. The steps that will resolve this are:

Stop project that runs in VS
Clean all IIS instances that VS temporarily created
Compile project and start that service again

answered Mar 15 '18 at 15:46

Yusubov

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"An operation is not legal in the current state" error when trying to launch ASP.NET project in VS2013?

3 Answers3