Fritz 13 creating custom openings training database

Ive been using Deep Fritz 13 to create custom opening training exercises.  However often after putting in a bunch of variations I save the file, and then when I attempt to select it for openings training Fritz says it cannon access the Database or it says the data base is not valid for openings training.  This doesnt always happen and it is maddening trying to figure out why its happeing.  I cannot see any difference between these databases and the ones that work......anyone?

I'm not 100% sure but I think the games in the database can't have the result: 1-0, 0-1 etc. Having even one game with a result can render the whole database invalid.

That may be your problem.

little late to the thread, but did you ever figure that out? im having the same issue