[Lava]

But the 2nd visit happens only with Skie in the party and after a couple of friendship talks:

Code:

IF
InParty(Myself)
Global("L#2SDMissiniReturns","GLOBAL",0)
OR(2)
Global("L#2SDSkieFriendshipActive","GLOBAL",2)
Global("L#2SDSkieFriendshipActive","GLOBAL",3)
THEN
RESPONSE #100
RealSetGlobalTimer("L#2SDMissini2Time","GLOBAL",600)
SetGlobal("L#2SDMissiniReturns","GLOBAL",1)
END

IF
CombatCounter(0)
InParty(Myself)
!See([ENEMY])
See(Player1)
Global("L#2SDMissiniReturns","GLOBAL",1)
!StateCheck("L#2SDSkie",CD_STATE_NOTVALID)
!StateCheck(Player1,CD_STATE_NOTVALID)
RealGlobalTimerExpired("L#2SDMissini2Time","GLOBAL")
THEN
RESPONSE #100
StartCutSceneMode()
CreateCreatureObjectDoor("L#2SDMES",Player1,0,0,0)
Wait(4)
SetGlobal("L#2SDMissiniReturns","GLOBAL",2)
Wait(2)
EndCutSceneMode()
ActionOverride("L#2SDMES",StartDialogueNoSet(Player1))
END

Since she was never in the party, her friendship can't be set to 2 or 3 + as you can see, she must be in the party. That's the problem, even if that's not some incompatibility between mods, I can't give you the variable as we don't know what script could possibly make this happen. It doesn't look like it's this as at least one condition isn't met: her presence in the party.

If you want, you can send me a savegame that's happening right before the crash so I could see if it's going to happen on my game, but use a PM with a link to the zip. And make sure it's not happening on any other mod's area.