I hate wrong error messages. I hate messages that lead me in wrong direction. Yesterday I've spend too much time on resolving problem with VSS. I had to add new user to VSS. Pretty simple task.
I've started and bang: "Invalid DOS PATH \\server\vss\project\users"
I've checked path - it's OK.
Double checked. Again the same error.
I've checked my privileges - Full access.
I've made local copy of VSS repository - still the same problem.
It's time to search for solution on Internet.
Few click, and I've got it: no template.ini file in \\server\vss\project\users catalog.
So, I've copied ss.ini of one user to template.ini, removed unneeded lines, and task completed.
Full description of solution.
Whenever you are programming, please, make sure that error messages are meaningful to users. Try to give as many details as possible, it will help to solve problem.