I'm gonna post a duplicate of my comment here as a separate entry as the author seem to be active on other pages and this issue is still "bugging" (pun intended) me

Still crashes in BP Sandboxes when creating an item
https://imgur.com/a/mANoiED

missclick, ignore this comment

It's best to make a new topic for a new problem, as the old one was marked done so there aren't notifications.

I'm not able to reproduce this. I added a check for what the error says is the issue in the new version but I can't confirm.

Okay, I'm not sure how to reproduce it now either. It may be something specific like another mod interaction. It used to be a problem back then and I think it happened again recently so I went to look for any updates here, but didn't save the new bug report. I think it was from ctrl-clicking (or just LMB?) on an item, but Q-picking always worked fine. Maybe it was the sandbox mod issue after all and it was eventually fixed by its author. Sorry for bothering, everything seems fine now. I'll open a new issue with more details if I encounter it again.