fixed loading non challenge savegames and another crash

(same request as before but deleted my whole repo and forked it again to repair history)
Copied from old push request

As every filename contained _ (due to the foldername of the saves
(.ffill_saves) the check didn't really work.

Also escape does not return the string entered but null - this is more
consistent with what the user expects i think.

also added a Console.ReadKey to the other checks so the user has time to
read the error message if the error occurs.