Stuck on analyzing pallet

Some photos I try adding get stuck on analyzing pallet, and can’t be dithered unless I manually choose some colors. I’ve tried waiting on these photos for literally hours and it never finishes analyzing. I can’t really find a pattern, but the ones it does this on I’ve never been able to get to work.

:c would really like this fixed. I use this tool a lot. Any work arounds would be helpful too