Failed to queue test run: Unable to start the agent process(Visual Studio 2010)

Question

While trying to run all the unit tests in my solution(Visual Studio 2010) I am getting a 'Failed to queue test run xxxx@MACHINENAME 2010-06-23 14:01:36': Unable to start the agent process' error. Does anyone know what causes this particular error to occur and how to resolve it so that I can run my unit tests?

Thanks

Answer 1

I don't know if this is still the case for Visual Studio 2010, but you could have this same scenario in Visual Studio 2008. When breaking off a unit test run (i.e. when detecting erroneous code while debugging a unit test) it would leave a process running.

The process that is hindering execution for Visual Studio 2008 and has to be killed to be able to unit test again is VSPerfMon.exe. Might be wort a look for VS2010.

Answer 2

I know this question was asked long before .NET 4.5, but I've found that I get this error on VS2010 after installing .NET 4.5.

A "solution" (not the most helpful one - I know) is obviously to uninstall .NET 4.5. I guess / hope there will be an update to Visual Studio 2010 at some point to resolve this.

UPDATE

I had a similar error, when trying to run tests which used TypeMock. In order to solve the problem I opened up my solution in Visual Studio and selected Test - Edit Test Settings. In the Test Settings dialog I selected Hosts and switched it to Run tests in 64 bit process on 64 bit machine.