Error: rule group has empty discipline rules

I want to create an international championship based on San Marino. But when loading a save with a new database, the game gives the error "rule group has empty discipline rules", while the data package was calmly checked in the editor. I found out on the forums that this error happens because of backup commands. According to the advice, I deleted these backup commands, but the error remained. Could you help me with this? thank you in advance.