The script T_Sc_Sound_AmbientInsects throws a "Script Error: EXPRESSION" and will not start running if MournWeather is set to 7, i.e. between the quests "A Show of Power" and "A Mad God" in the Tribunal questline. The mechanics of this script are mostly copied from Sound_MournEnv, except that it checks if the player is in Almalexia during the ashstorm episode. It appears that this check is not working properly however, so this needs to be fixed.
It is impossible to return from the cavern in Galseah where the Winged Twilight resides without jumping, which is problematic due to the side quest where two NPCs join the player for hunting daedric cultists. Due to the poor AI in Morrowind, this causes them to get stuck in this cavern. To resolve this, the staircase leading there needs to be extended all the way down to the floor, but it currently ends in a platform slightly above the floor. The platform is located at the listed coordinates.
At least one of our new Khajiit races uses vanilla body part .nif files and textures. This causes incompatibilities with body replacer mods, most egregiously the seamless body replacer types. On top of that, a user reported missing textures that are likely related to this (somehow). Speficially, their Redguard parts were throwing texture errors when the parts were called on our Cathays, but working just fine on their Redguards. Robert's Bodies was the replacer used.
So after updating Tamriel rebuilt esm I start the game and in the game loading (not save loading) I get the notifications - missing necrom door - missing necrom key - unable to locate sigil amulet ayem , quam, shet, vehk, e oht in leveled item kha date amulets - native ebony gauntlet not found on athelyn savil
The book with the ID listed above is titled "Morrowind History: Andothren" when I highlight over it. However when I open the book it is titled "Morrowind Historia: Stonefall" (and contains the content for the later).
The lower platform in Galseah, Deep Caverns is missing a ladder, making the npc followers from the Avenge the Knights quest get stuck if you lead them down there, and the enemies there unable to chase you up the stairs.