It will help more people to become aware of the problem if the bug description is also posted here.
So here it is.
Crash on entering Sample Population for fact type (fact type that is in error mode).
Reproduce:
by adding the attched orm file to a new VS2013 sln.
FT: Profile has TimeStepSize. Enter '5 minutes' or '5' ...
Then this unhanndled exception occurs.
System.NullReferenceException was unhandled
Message: An unhandled exception of type 'System.NullReferenceException' occurred in Microsoft.VisualStudio.VirtualTreeGrid.dll
Additional information: Object reference not set to an instance of an object.