"Formula can not be evaluated" error message

In both 11.300 and 11.311, when I open my Dragonbane campaign for which I have not installed the official content module but instead created all the items manually, I always get three messages "Formula can not be evaluated".

I believe that had something to do with items that I made, apparently improperly.

But I don't have the slightest clue which of the many items might be causing these error messages to appear. Any way to find out where the problem is caused that is producing these messages?