Also reported on reddit:
On the last upgrade for Cartie's mission, 5/6 crystal bot upgrades, and everytime i goto use the final upgrade the game crashes. Dont know if this is because of her mission, the crystal bot or too many upgrades causing the problem.
Ps5, upgrading it past 5 wasnt a problem in the next run i did, so i dont know what was causing it to crash before.
Yeah, i even tried switching the upgrades to see if that did anything and still crashed it. It was only for that one run though, the next run i was able to go past 6 upgrades and get the quest done.
I've encountered a game breaking bug on endless dungeon. The final mission for Cartie you have to upgrade the bot 6 times, the game keeps crashing when I'm trying to put in the final upgrade. I've tried 5 times and it keeps doing it.
Also the version of the game for the ps5 is 1.000.004