I have seen this on several machines. Do this first, create a custom enum. In fact use this one below:Public Enum MySampleType As Integer
First = 0
Second = 1
Third = 2
End Enum
Once created, build the solution. Go back to the PopulationEnum and type MySample in the search field. See if this displays the new enum we just created. If so, I have an idea of what might be happening on your machine.