Whenever I try to use the creative pendant this happens: http://prntscr.com/8oj0xf
Edit: Also does this when I exit the reward selector one
Edit 2: This seems to only happen in Galacticraft planets (moon specifically), not a big deal.

There is always a crash log, check the server log.

Do you have any error logs by chance?

It doesnt seem to give an error :/ It just says I lost connection and stops the singleplayer server

This isn't really that bug of an issue. I created this before actually doing some testing. Sorry about that.