I have 2 folders

Microsoft visual foxpro 9
Microsoft visual foxpro 9 copy

I try to open _base (checkbox) from "Microsoft visual foxpro 9" and I receive an error message saying that the vct is invalid

I try to open _base (checkbox) from "Microsoft visual foxpro 9 copy" and everything works fine

I delete "Microsoft visual foxpro 9"
I rename "Microsoft visual foxpro 9 copy" to "Microsoft visual foxpro 9" and then I make another copy of this folder which gives me another "Microsoft visual foxpro 9 copy"

I try to open _base (checkbox) from "Microsoft visual foxpro 9" and I receive an error message saying that the vct is invalid

I try to open _base (checkbox) from "Microsoft visual foxpro 9 copy" and everything works fine

What's going on here?