I'm on build 6249 too, I've got 60 hours of gameplay in my savegame and will not restart another game.

When the game crashes, I get a "Can't use "Obj" function set" error dialog in Windows.

Time to play an older King's Bounty game... :-(

I would NOT restart for "Can't use "obj" function set" sort of error and if you started on build 6249. Although I'm boggled at what technique or units you are using to trigger this.

I'm worried because it seems like build 6246 saved game with 6249 build seems the most "stable"? :(

Yeah, I get the obj error once in a while too. I just try a different technique or different units. When I played (without crashing against guilford), I was using Soothsayer/Mage as Hero type.

Black Dragons, Archdemons, Red Dragons, and Ancient Ent. I relied mostly on Ancient Phoenix and Greasy Mist. Occasional Turn Back Time.

I did use some Rage Skills, no problems.

Are you using any user patches too?

[edit]
I think I know why it is crashing. It is all related to the now bugged Book of Evil. If you let the boss cast Book of Evil, kill it SUPER fast or redo your fight to try to have him NOT cast book of evil.

Thanks a lot ckdamascus

I will try that book of evil stuff, I am using a human stack of units, I've started the game on an earlier build.

I don't use any user patches. Probably my stack is still a bit weak, I will clean Demonis and Hades first.

Thanks again & Regards

Oh sorry, I mean, when the enemy hero casts it, it tends to crash the game.

The book of evil is broken now, in a bad way. It is super weak and has like -100/0 charges or something absurd.

I've seen them in combat in build 6249 without ill effects, but I get a weird feeling it can cause crashes. I've started to crash a LOT more now that I'm in Demonis / New Kordar.

Wow! After 6 or 7 tries with autocombat, I managed to kill the book of evil asap and won the battle. Thanks a lot man!! You're probably right, it's the book of evil that bugs everything down. Good to know.

it is also skald that bugs, his ability
when i disable his ability or kill him before he use it i finish the battle without problems

one more battle against skalds in army, same problem and same solution

Pretty sure I'm getting the same error msg/code randomly. For sure, mine have nothing to do with Book of Evil being cast as I have not seen it in my game as yet.

I'll have to pay closer attention to Skalds, however. I don't have any in my army, yet I have just started seeing them in enemy armies. And it has just been recently that the crashing started with that obj function error.