I installed FCOM before beginning this character, and previously, was able to enter this cell with no problem. I haven't made any changes to the installed mods (that is, I haven't updated any to a newer version, or added any news mods - everything is exactly the same as when I started this character).
This is very frustrating - I have two quests which both require me to enter this cell, but I cannot without crashing.
If anyone is interested in trying to diagnose the problem, I'd be happy to post a game save file somewhere you could load to try to debug this. If anyone can provide any advice on how I might go about debugging this myself, I'm happy to listen.
Anyhow, I guess as a starting point, the load order with all the mods listed would be helpful:
Oblivion.esm
Francesco's Leveled Creatures-Items Mod.esm
Francesco's Optional New Items Add-On.esm
Oscuro's_Oblivion_Overhaul.esm
Mart's Monster Mod.esm
FCOM_Convergence.esm
Unofficial Oblivion Patch.esp
UOP Vampire Aging & Face Fix.esp
Oblivion Citadel Door Fix.esp
DLCShiveringIsles.esp
Unofficial Shivering Isles Patch.esp
Francesco's Optional Chance of Stronger Bosses.esp
Francesco's Optional Chance of Stronger Enemies.esp
Francesco's Optional Chance of More Enemies.esp
Francesco's Optional Leveled Guards.esp
FCOM_Francescos.esp
FCOM_FrancescosItemsAddOn.esp
FCOM_FrancescosNamedBosses.esp
DLCHorseArmor.esp
DLCHorseArmor - Unofficial Patch.esp
DLCOrrery.esp
DLCOrrery - Unofficial Patch.esp
DLCMehrunesRazor.esp
DLCMehrunesRazor - Unofficial Patch.esp
DLCSpellTomes.esp
DLCSpellTomes - Unofficial Patch.esp
Bob's Armory Oblivion.esp
Cheat Bob's Armory Oblivion.esp
FCOM_BobsArmory.esp
Oblivion WarCry EV.esp
FCOM_WarCry.esp
Oscuro's_Oblivion_Overhaul.esp
Mart's Monster Mod - Additional Enemy NPC Vars.esp
FCOM_Convergence.esp
FCOM_EntropicOrderRebalance.esp
FCOM_RealSwords.esp
FCOM_DurabilityAndDamage.esp
Mart's Monster Mod - More Wilderness Life.esp
Mart's Monster Mod - More Passive Wildlife.esp
FCOM_SaferRoads.esp
Mart's Monster Mod - Extra Wounding.esp
Mart's Monster Mod - No Undead Rise.esp
Mart's Monster Mod - Dungeons of MMM.esp
Mart's Monster Mod - Gems & Gem Dust.esp
Mart's Monster Mod - Hunting & Crafting.esp
Mart's Monster Mod - Farm Animals.esp
Mart's Monster Mod - Diverse WaterLife.esp
Mart's Monster Mod - Slof Horses Complete.esp
Mart's Monster Mod - Diverse Runeskulls Loot G&GD.esp
FCOM_DiverseGuardUnity.esp
FCOM_BobsGuardUnity.esp
FCOM_HungersUnitySI.esp
FCOM_FriendlierFactions.esp
FCOM_MoreRandomSpawns.esp
FCOM_MoreRandomItems.esp
Mart's Monster Mod - Shivering Isles.esp
OOO-WaterFish.esp
DLCFrostcrag.esp
DLCFrostcrag - Unofficial Patch.esp
Knights.esp
Knights - Unofficial Patch.esp
Mart's Monster Mod - City Defences.esp
FCOM_Knights.esp
Harvest [Flora].esp
Harvest [Flora] - Shivering Isles.esp
Harvest [Flora] - DLCFrostcrag.esp
Mart's Monster Mod - Resized Races.esp
Bashed Patch, 0.esp