Hey, thanks for getting back to me.
It seems I occur randomly and it’s usually once I’ve done all or nearly all, my adjustments I have the photos loaded directly to my camera roll.
Changing one or two things is generally fine, and it seems to be on all RAW files, I did lower the amount of Undo limit to 30 thought that might help and have changed the save interval to 30. After doing this I edited one picture developed fine then went to do frequency separation and it crashed again lucky it was saved by then. It just seems to be unstable with all RAW files I have not just any particular ones.