VS402325 Work item type category Microsoft.TestPlanCategory does not exist in project
I tried to create a Test Plan on our Team Foundation Server today but I got this error message:
VS402325: Work item type category Microsoft.TestPlanCategory does not exist in project xxx
I solved this this by following the directions in this MSDN article to enable the Test Plan feature on the project.
There were no search results at the time of writing about this error message, I thought I may as well post one.