Adding an attachement to the Sharepoint list

Hello,

I have a sharepoint list with attachement column. When I want to edit existing record (add an attachement) problem occurs (after "Save" button click). I have to choose the categories once again and then it works. Do you have any idea why is it like this?

These two categories where the problem occurs are cascading dropdown:

This problem means in English "Record is required or invalid. Correct the record and try again"