I'm up to level nine.
Doing Knights Of The Nine first.
As I left Carrol I gave Weynon Priory a visit to drop off the Amulet and deal with quest later.
As I went in, it was all black with things floating.
Before I started the game, I updated OOO 1.33 to 1.34. That was after I backup the data file.
The game runs fine. I been in other buildings in Carrol and there are fine.
I went into the cave after I visit the Priory and it is good.
I doubt its OOO problem.
I think its a texture problem even though there is no purple or any of these '!' marks.
Here are my mods-


Oblivion.esm
EnhancedWeather.esm
Oscuro's_Oblivion_Overhaul.esm
TheHungerGamesArena.esm
Unofficial Oblivion Patch.esp
UOP Vampire Aging & Face Fix.esp
Oblivion Citadel Door Fix.esp
DLCShiveringIsles.esp
EnhancedWeather.esp
EnhancedWeather - Darker Nights, 80.esp
PowerAttack Voicemod.esp
PowerAttack Voicemod - The Shivering Isles.esp
ClocksOfCyrodiil.esp
Damsels In Distress.esp
P1DseeYouSleep.esp
Populated Prisons.esp
DLCHorseArmor.esp
DLCOrrery.esp
DLCVileLair.esp
P1DseeYouSleep - DLCVileLair.esp
DLCMehrunesRazor.esp
DLCSpellTomes.esp
MaleBodyReplacerV4.esp
ANBRobertsCupSizes.esp
RTFemaleReplacerV12.esp
DLCThievesDen.esp
Oscuro's_Oblivion_Overhaul.esp
OOO-WaterFish.esp
The Duelists.esp
DLCFrostcrag.esp
Knights.esp
UNKNOWNYMOUS Social NPCs.esp
Lynges Unlimited Death Reload Time.esp
Unequip Broken Armor.esp
OOO-Level_Stock.esp
Sonia.esp
Timescale 10x Real-Life.esp
SnArrowEffects.esp
MazogaCompanion.esp
HungerGamesAddon.esp

Here are the pic that I promise you-
http://i140.photobucket.com/albums/r11/Gerza71/Oblivion2011-02-0509-44-49-06.jpg
http://i140.photobucket.com/albums/r11/Gerza71/Oblivion2011-02-0509-44-52-22.jpg
http://i140.photobucket.com/albums/r11/Gerza71/Oblivion2011-02-0509-44-55-24.jpg

i take it your using boss and obse?

Yes.

Looks like someone accidentally deleted the interior when making their mod -- probably clicked on the wrong piece when deleting something and had the interior selected instead of whatever they meant to delete. Look through any mods that touch the priory and see if they delete the interior by mistake.

All I found is http://i140.photobucket.com/albums/r11/Gerza71/WeynonPrioryedit.jpg through edit. I tried it did not made any difference. I still have that back up and see that fix it.

That would do it. An ESM cannot edit cells or worldspaces belonging to another ESM or you get exactly what you're seeing. My guess is that TheHungerGamesArena.esm didn't intend to make the edit (stupid CS water bug) and they may not even know it's happened. You should report that to the mod's author, with the pics to illustrate it. They'll need to fix that.

@ Arthmoor you are right. I deactivated the mod and I can see Weynon Priory in full. I will report it to him. I did edit it by removing that value, but did not made any difference. Thank you for all that helped.