Dear friends,

each time I try to open a particular program (Mathcad 15) I get the message 'Failed to create empty document'.
Then the program goes on but is useless because I cannot open an new or existing document.
In my opinion this is a permission problem because the program runs without a problem within the hidden administrator account.
I tried a lot of things:
running as administrator
setting permissions for the program
taking ownership

nothing works.
This is very annoying because I have a huge library of MCad document I can't open anymore.
Well I could when I login as hidden administrator but this is not a good idea I suppose.
OS = win 10 pro.