Why does custom Build Process Template executing PowerShell fail - powershell

Question

I've modified a custom build process template to execute Powershell on the build server. This is so I can run some scripts that will automate the deployment of our SharePoint solution. Everything was working fine up until I upgraded the build servers Powershell version from 2.0 to 3.0 (which needed to be done as I was installing SCVMM Admin Console 2012 and Powershell 3.0 was a pre-requisite).
In the build template itself, I'm using a Microsoft.TeamFoundation.Build.Workflow.Activities.InvokeProcess work flow item to execute the PowerShell command with the following properties:
Arguments : String.Format(" ""& '{0}' -DropLocation '{1}' {2} "" ",
ScriptFilename, BuildDetail.DropLocation, PostDropScript2Arguments)
FileName : "powershell"
OutputEncoding :
System.Text.Encoding.GetEncoding(System.Globalization.CultureInfo.InstalledUICulture.TextInfo.OEMCodePage)
Now every time I try to execute the build, I get the following error:
Exception Message: File not found: PowerShell (type
FileNotFoundException) Exception Stack Trace: Server stack trace:
at
Microsoft.TeamFoundation.Build.Workflow.Activities.InvokeProcess.ProcessWrapper.Start()
at
Microsoft.TeamFoundation.Build.Workflow.Activities.InvokeProcess.InvokeProcessInternal.RunCommand(AsyncState
state) at
System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr
md, Object[] args, Object server, Object[]& outArgs) at
System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(IMessage
msg, IMessageSink replySink)
Exception rethrown at [0]: at
System.Runtime.Remoting.Proxies.RealProxy.EndInvokeHelper(Message
reqMsg, Boolean bProxyCase) at
System.Runtime.Remoting.Proxies.RemotingProxy.Invoke(Object NotUsed,
MessageData& msgData) at System.Func2.EndInvoke(IAsyncResult
result) at
System.Activities.AsyncCodeActivity1.System.Activities.IAsyncCodeActivity.FinishExecution(AsyncCodeActivityContext
context, IAsyncResult result) at
System.Activities.AsyncCodeActivity.CompleteAsyncCodeActivityData.CompleteAsyncCodeActivityWorkItem.Execute(ActivityExecutor
executor, BookmarkManager bookmarkManager)
Inner Exception Details:
Exception Message: The system cannot find the file specified (type
Win32Exception) Exception Stack Trace: at
System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo
startInfo) at
Microsoft.TeamFoundation.Build.Workflow.Activities.InvokeProcess.ProcessWrapper.Start()
It seems like the build is no longer able to link the "powershell" command with the actual PowerShell file.
I've manually gone onto the build server and typed "powershell" into a command line and it started PowerShell, as expected.
Has anyone else experienced this issue before?
Thanks very much

Answer 1

Add the full filepath to powershell.exe in the invokeprocess step in your workflow and it should always work (I would not trust the environment-settings for this)
And know, logging in on the server under your own account is not equal to the build server running under a specific account.

Answer 2

In my case same error occurred after deploying Windows Managment Framework 3.0.
It was solved by restarting build controller and agent.