All of a sudden I've got a weird missing mesh problem (the red triangle thing). Everytime I load a save (I even tried earlier ones) after a minute or so my character is surrounded by the red triangle. I tried dropping everything in my inventory but the problem persists. The weird thing is the red triagle only pops up after running around for a while.

Right before this problem I installed some mods (mostly radio mods and some building mods like skyforest and Movin On Up). After deactivating those mods the problem seems to stay.

Also, all of a sudden I got blurry textures on some buildings and terrain. This goes away after loading or cell transition.

Is my game screwed all of a sudden? I would hate to completely reinstall the game and the character.

For info, my load order:

Fallout3.esm
Anchorage.esm
ThePitt.esm
BrokenSteel.esm
PointLookout.esm
Zeta.esm
Unofficial Fallout 3 Patch.esm
FallsChurchMetroFix.esm
PointLookout-FollowersGetToGo.esm
Impervious Power Armour.esm
CRAFT.esm
CALIBR.esm
Project Beauty.esm
FO3 Wanderers Edition - Main File.esm
Mart's Mutant Mod.esm
Companion Core.esm
Companion Share & Recruit.esm
RobCo Certified v2.esm
Wasteland Whisperer v2.esm
Enhanced Weather - Rain and Snow.esm
Xepha's Dynamic Weather.esm
StreetLights.esm
DCInteriors_ComboEdition.esm
TheInstitute.esm
shopping-spree.esp
CEI - CaesarrulezExcessiveInteriorsEN.esp
FO3 Wanderers Edition - Alternate Travel.esp
Unofficial Fallout 3 Patch - Operation Anchorage.esp
Unofficial Fallout 3 Patch - The Pitt.esp
Unofficial Fallout 3 Patch - Broken Steel.esp
Unofficial Fallout 3 Patch - Point Lookout.esp
Unofficial Fallout 3 Patch - Mothership Zeta.esp
UF3P Crane Fix.esp
FireLightFix.esp
DarNifiedUIF3.esp
I'll Touch What I Want.esp
Faster PipBoy Light.esp
praiseatom.esp
Megaton Tweaks 1.28 (no podium).esp
CASM.esp
RadioBlues.esp
People_Radio.esp
CONELRAD 640-1240.esp
Existence2.0.esp
CivilDefenseBroadcastSystem.esp
Loki_HistoricSpeeches_v1.esp
RadioTenpenny.esp
TheDaysofChristmasRadio.esp
UPP - Pack 1.esp
UPP - Pack 2.esp
UPP - Experience Perks.esp
UPP - Quest Perks.esp
Ex Libris - PreWar Book Titles.esp
NotSoFast.esp
HeirApparent.esp
IntoTheDeepWoods.esp
PLweightadjust.esp
The Mantis Imperative - Mantis.esp
The Mantis Imperative - Jello.esp
AReasonedArgument.esp
MegatonContracts.esp
A Trail of Crumbs.esp
0rb_ComicPack1.esp
Not alone in the Wasteland anymore.esp
BoSPatrols.esp
BlackWolf Backpack.esp
BlackWolf Backpack - Vendor Script Replenish.esp
Glow Sticks.esp
Kukri by MadCat and AJ.esp
MaintenanceShed.esp
D.C. Confidential.esp
MoreMapMarkers.esp
Treasure Maps_Underground.esp
Treasure Maps_Secrets of the Wasteland.esp
Treasure Maps_Bobblehead Edition.esp
Treasure Maps_A Fist Full of Caps.esp
MTC MoreGuardsInBigTown.esp
MovinOnUp1.6.esp
PeachCreekRuins.esp
skyforest.esp
AIM.esp
BunkMod - Megaton House - v0.01.001.esp
BunkMod - Tempenny Suite - v0.01.001.esp
Canterbury Estates 0.8 beta.esp
SuperDuperBasemant.esp
WastelandHomes.esp
01AtM - Firefly Ranch.esp
UrgeAndaleHouse.esp
UrgeScientistShelter.esp
UrgeSpringvaleHome.esp
DCInteriors_DLC_Collectables.esp
WIP_BigTown.esp
VulturesRest.esp
FLAK.esp
FO3 Wanderers Edition - Main File.esp
FO3 Wanderers Edition - DLC Anchorage.esp
FO3 Wanderers Edition - DLC The Pitt.esp
FO3 Wanderers Edition - DLC Broken Steel.esp
FO3 Wanderers Edition - DLC Point Lookout.esp
FO3 Wanderers Edition - DLC Mothership Zeta.esp
FO3 Wanderers Edition - Followers Enhanced (BrokenSteel).esp
DarNifiedUIF3_FWE.esp
Refurbish [OA] - FWE.esp
Refurbishes [ALL].esp
Tailor Maid.esp
Tailor Maid Anchorage.esp
Tailor Maid PITT.esp
Tailor Maid Brokensteel.esp
Tailor Maid ZETA.esp
WeaponModKits.esp
WeaponModKits - FWE Master Release.esp
WeaponModKits - OperationAnchorage.esp
WeaponModKits - ThePitt.esp
WeaponModKits - BrokenSteel.esp
WeaponModKits - PointLookout.esp
WeaponModKits - Zeta.esp
GaussCompleteBeta.esp
ZL-ACR.esp
ZL-SVD-CALIBR.esp
ZL-MP5 Pack.esp
WinterizedT51bDX.esp
Outcast DX.esp
Tribal_DX.esp
BoS_FOOKedition_Armor.esp
Dogmeat Leather Armor - CRAFT.esp
Powered Power Armor.esp
PPA - Operation Anchorage.esp
PPA - Broken Steel.esp
PPA - FWE.esp
Companion Core DLC Addon.esp
Wasteland Whisperer v2 Broken Steel Addon.esp
RobCo Certified v2 Mechanist's Edition.esp
RobCo Certified v2 Zeta Addon.esp
Mr Smith's Scrapyard.esp
Salvagable cars.esp
EVE.esp
EVE Operation Anchorage.esp
EVE - FWE Master Release.esp
Mart's Mutant Mod.esp
Mart's Mutant Mod - DLC Anchorage.esp
Mart's Mutant Mod - DLC The Pitt.esp
Mart's Mutant Mod - DLC Broken Steel.esp
Mart's Mutant Mod - DLC Zeta.esp
Mart's Mutant Mod - FWE Master Release.esp
Mart's Mutant Mod - Project Beauty + FWE.esp
RaiderMercenaryExpanded.esp
RaiderMercenaryExpanded[M&W].esp
tubunarCombatVanilla.esp
tubunarCombatFWE.esp
tubunarFWE.esp
KH_FWE Hellfirefix.esp
RobCo Certified v2 Omnipatch.esp
A New Life.esp
Path to Redemption.esp
megalight.esp
Enhanced Weather - Weather Sounds in Interiors.esp
Realistic Interior Lighting.esp
Realistic Interior Lighting - BS.esp
Realistic Interior Lighting - OA.esp
Realistic Interior Lighting - PL.esp
Xepha's Dynamic Weather - Main.esp
Xepha's Dynamic Weather - Anchorage.esp
Xepha's Dynamic Weather - The Pitt.esp
Xepha's Dynamic Weather - Broken Steel.esp
Xepha's Dynamic Weather - Point Lookout.esp
Xepha's Dynamic Weather - Sandstorm.esp
Xepha's Dynamic Weather - Sandstorms Damage Armor.esp
Xepha's Dynamic Weather - NightTime SneakBoost.esp
Xepha's Dynamic Weather - Rain.esp
Bashed Patch, 0.esp
Clear Cell Buffers every Cell.esp

Total active plugins: 171
Total plugins: 189

Try switching on and off your archive invalidation :brokencomputer:

Try deactivating fifteen or twenty mods. Some people have a problem with random meshes disappearing when running large numbers of mods. If it works, add in a couple at a time until you find the max number of mods your game can handle before it pukes stuff back up.

Ok, an update. I could "solve" the problem by reverting to an earlier save (a lot of saves earlier actually). All went well until yesterday when the problem occured again at the Meresti Trainyard. This time it seemed I was able to reproduce the problem. Each time I loaded an earlier save and passed a certain point in the world (the shelves next to one of the buildings at the trainyard) the missing mesh popped up. I made sure to don't loot anything of the shelves so it couldn't be a missing mesh from something I picked up.