Can't use crests

Game crashes whenever I try and enhance crests. Specifically what happens, I select a crest and hit enhance, the frame rate slows to a crawl, and then the game crashes within a few seconds.

The rest of the game works fine, I can fight the tower boss without any issue, it's just when I try and enhance a crest.

The only thing I found from googling the issue was mention of possibly having too many crests, but even if that's the case, I still can't use them so how the hell can I fix it.

Also if having too many of something in an idle game causes it to break, that is impressively bad design. Even for a game that has had this many issues.