Disappear, no, but he should come back in a day or so. Have you tried leaving the map and coming back?
Another development, the game only crashes if I rest long enough to memorize new spells. If I'm interrupted before that happens, the game doesn't crash.
I think re-activating the module might clear this up. It sounds like a process is running and cannot complete.
I'm sorry to hear that, maybe someone a bit wiser in the ways of the mod's workings will post and help you.
I'm not sure if I've said this yet, but the game crashes if I try to access the interface in anyway but only AFTER RESTING to restore spells. I can move around for a bit if I don't right click, open the main menu, or open the inventory.
Do you have any buffs active when you rest? This used to cause random crashes in previous versions. If you do have a buff still active, try letting it wear off first then try resting. And of course, don't rest in a RE area.
This file is from right before the bug happens. Rest in any area, and as soon as you right click or open a menu, the game will crash.
I am going back through to ensure I haven't missed anything and I just noticed that in the "Thief!" quest in Nulb, there is a mix up. Dala tries to pick a pocket and gets caught. I tell Rentch that he is no good and combat is supposed to start but Dala is lying on the floor and it says I am wiping off blood from my sword. There was no combat or anything like that. Also, if I give a coup-de-gras to Dala, she will be back crying. Pearl just takes off.
As for the problem with level 17 or 18 Druid... Before restarting, I had Meleny up at that level and there were no problems.... Then again, I don't get the spell enhancement feats which it sounds like the person having the problem does. It just doesn't seem like a good thing because I use other spells.
ShadyElf, your WIS score is 70 and as a result you appear to have overloaded the game with too many spells memorized. Trimming it down solves issue. However, an unnatural score such as that indicates that you have used the console. That's fine if you want to play that way, but be aware that this pretty much voids Co8 'warranty'.