Randomly when I'm playing FO3 I I come across these bars and lines that fill up my entire screen... sometimes after looking at them for a while everything but the HUD goes black. Sometimes not. If I look in the opposite direction, they go away, but if I re-turn they return. It mostly happens in the wasteland, but sometimes it happens in megaton and I've even had it happen in Anacostia Crossing. I'm pretty sure it's one of my mods that's screwing it up, but I don't know what exactly it is that's being screwed up. A mesh? A texture? Is it a crash that just happens? I've noticed that saving and reloading doesn't work, but exiting, restarting the game and loading does. I don't know. It's really a mystery to me. What's causing this? What general area should I look at to fix this? CAN I fix this?

Post your load order. No one can help you if you don't.

Here is the full list. It's pretty damn long. I've used FO3edit to make several of them compatible.

This is the "Load Order Report"

"Fallout3.esm
Lings.esm
* This mod does not exist in the current template

PointLookout.esm

Anchorage.esm

ThePitt.esm

BrokenSteel.esm

Zeta.esm

LingsDLC.esm
* This mod does not exist in the current template

RH_IRONSIGHTS.esm
* This mod does not exist in the current template

20th Century Weapons.esm
* This mod does not exist in the current template

Destruction.esm

CRAFT.esm

CALIBR.esm

StreetLights.esm

Mart's Mutant Mod.esm

Project Beauty HD version.esm

SShop.esm
* This mod does not exist in the current template

Shooter.esp
* This mod does not exist in the current template

DarNifiedUIF3.esp

CRAFT - Activation Perk.esp

Cryo Weapons - Vanilla.esp
* This mod does not exist in the current template

Tactical Weapons by gRs Frederyck.esp
* This mod does not exist in the current template

DK_BulletTime.esp

Sprint Mod.esp
* This mod does not exist in the current template

Pause.esp
* This mod does not exist in the current template

GalaxyNewsRadio100[M].esp

TUPAM.esp
* This mod does not exist in the current template

Outcast DX.esp
* This mod does not exist in the current template

ACE2-1b.esp
* This mod does not exist in the current template

UPP - Pack 1.esp

sunglassescollection.esp
* This mod does not exist in the current template

UPP - Pack 2.esp

SniperZooming.esp

Destruction - Main.esp

Destruction - Main - Statics.esp

Destruction - DLC.esp

CombatEnhanced-Package v02.esp
* This mod does not exist in the current template

20th Century v4 ALIVE (TEST Container).esp
* This mod does not exist in the current template

dD-Full Screen Blood.esp
* This mod does not exist in the current template

20th Century v4 ALIVE (Vendor).esp
* This mod does not exist in the current template

20th Century v4 ALIVE (NPC_Settler).esp
* This mod does not exist in the current template

Sensible Dismemberment.esp
* This mod does not exist in the current template

20th Century v4 ALIVE (Raider).esp
* This mod does not exist in the current template

richvendors.esp
* This mod does not exist in the current template

20th Century v4 ALIVE (RivetCity).esp
* This mod does not exist in the current template

20th Century v4 ALIVE (Brotherhood_Outcast).esp
* This mod does not exist in the current template

WeightAmmo.esp
* This mod does not exist in the current template

KillableKidsNormalHealthOptional.esp
* This mod does not exist in the current template

Destruction - DLC - Statics.esp

Stealth Kills Enabled.esp

Triage.esp
* This mod does not exist in the current template

XFO_Perk_rebalance.esp
* This mod does not exist in the current template

XFO_Perk_paths.esp
* This mod does not exist in the current template

Colossus Headgear.esp
* This mod does not exist in the current template

kikaiEquipment.esp
* This mod does not exist in the current template

Monster_Costumes.esp
* This mod does not exist in the current template

Dragonskin Tactical Outfit.esp

DragonskinBonusPack.esp
* This mod does not exist in the current template

CBOv1.4.esp

WeightRebalance.esp
* This mod does not exist in the current template

Welcome To The Wasteland.esp
* This mod does not exist in the current template

SShopItems.esp
* This mod does not exist in the current template

WasteWearGloves.esp
* This mod does not exist in the current template

RandomExtraTraps.esp
* This mod does not exist in the current template

Mart's Mutant Mod.esp
Requires Mart's Mutant Mod.esm

Mart's Mutant Mod - No Floaters.esp

Mart's Mutant Mod - Linged.esp
* This mod does not exist in the current template

bzBodySuits.esp
* This mod does not exist in the current template

FEV_Subjects.esp
* This mod does not exist in the current template

BetterHeadshots.esp
* This mod does not exist in the current template

Realistic View Mod.esp
* This mod does not exist in the current template

Malos_BodyResize.esp
* This mod does not exist in the current template

AdvancedReconGear.esp
* This mod does not exist in the current template

Pip-Boy StealthBoy Addon.esp
* This mod does not exist in the current template

Mart's Mutant Mod - No Geckos.esp

Mart's Mutant Mod - No Ghoul Raise.esp

Mart's Mutant Mod - No Wanamingos.esp

Mart's Mutant Mod - Hunting & Looting.esp

Mart's Mutant Mod - Natural Selection.esp

Deadly Throwing Knives.esp
* This mod does not exist in the current template

bltc.esp

BLTC Immersion Patch.esp

NCHiddenSKillChecks.esp
* This mod does not exist in the current template

RH_IronSights_Elite_VanillaPlugin.esp
* This mod does not exist in the current template

RealPhysicsLessCarExplosions.esp
* This mod does not exist in the current template

ShellRain.esp
* This mod does not exist in the current template

1PipboyPDA.esp

20th Century v4 ALIVE (SuperMutant).esp
* This mod does not exist in the current template

Onehitter's Combat Realism.esp
* This mod does not exist in the current template

Onehitter's Increased Durability Add-On.esp
* This mod does not exist in the current template

20th Century v4 ALIVE (Chinese Ghoul).esp
* This mod does not exist in the current template

Onehitter's Ammo Scarcity Add-On.esp
* This mod does not exist in the current template

20th Century v4 ALIVE (Talon_Regulator).esp
* This mod does not exist in the current template

Onehitter's Realistic Carry Weight.esp
* This mod does not exist in the current template

StreetLights - Wasteland.esp

18inchCSLatinMachete.esp
* This mod does not exist in the current template

Magic Fingers Perk No Karma.esp
* This mod does not exist in the current template

NoStupidExplosiveCars.esp
* This mod does not exist in the current template

megalight.esp

Remove That Glove.esp
* This mod does not exist in the current template

PersonalTerminal.esp
* This mod does not exist in the current template

Dree Perks.esp
* This mod does not exist in the current template

Dree Perks Requested by Fans .esp
* This mod does not exist in the current template

Faster PipBoy Light.esp
* This mod does not exist in the current template

pip60.esp
* This mod does not exist in the current template

bzArmour-non-nvde.esp
* This mod does not exist in the current template

Better Looking Combat Shotgun.esp
* This mod does not exist in the current template

Barter Master.esp
* This mod does not exist in the current template

VisionMod-Tom.esp
* This mod does not exist in the current template

3EFdrg.esp
* This mod does not exist in the current template

bzArmour.esp
* This mod does not exist in the current template

Selective Fire.esp
* This mod does not exist in the current template"

What I really want to know though, is what kind of error is occurring; that way I can troubleshoot. This mod list may not help.

Have you made sure that it's not a hardware component overheating? A screenshot would help, too.

I'm not sure how to check if it's a hardware component. I suppose it could be just adding up the number of mods that I use, but I would think that would cause lag, or a crash.

How does one post screenshots? I would've earlier if I knew how to.

When graphics cards overheat you tend to get artefacts like that. Insufficient cooling and a powerful card could result in it overheating before that starts to impact performance.

OP: Does your screen resemble http://a.imageshack.us/img8/513/parkfy.jpg? That's a different game (The Sims 3), but that's what I keep thinking could be happening. Without a screenshot I'm just guessing. http://a.imageshack.us/img6/7910/73779675.jpg.
I gathered from my Googling that it was video card overheating. Understandable as my case is a bit like a bread oven, not much in the way of ventilation, and only one exhaust fan in the back. My system isn't really a gaming system, but I pretend it is

The only time I had a graphic issue sorta similar with Fallout was when I was trying to get a custom armor into the game and it went all screwy. More my lack of knowledge in that area of modding than hardware issue. Removal of the offending mesh fixed it. But in the case of screwy textures like the above images I'll be getting a better case I think

That sounds a lot more like a hardware issue as the others have suggested, does it look similar to http://i13.photobucket.com/albums/a288/sinderelly/mimironhardmode.jpg at all?

You can take screenshots by hitting your PrintScreen key and then looking in your Fallout 3 directory. There are a number of free programs that can show you what your GPU temperature is if you want to check for overheating.

As everyone has been saying, you need to make sure your card isn't overheating our overclocked first.

However, I believe Oblivion also had similar problems for some people. It may have had something to do with using mods that tried to use more video memory than you had available on your card. How much memory does your card have? And what graphic settings are you using? Sometimes things like driver updates can fix those things. I had it in Oblivion for a bit, but I never replaced my card or fixed any kind of overheating problem and I eventually got it to go away.

MystykStar, they do look similar. I'm not sure how to check my hardware or cooling, I just know that it happens with mods installed. if it's using more space than I have, how can I check that?

LividLindy, It looks more like an obstruction than a texture issue. Going into wireframe mode shows a bunch of extra lines going all over the place. I know how to TAKE screenshots, just not how to upload. Can I get a recommendation for a free program that will monitor this? And will it work during Fallout 3?

Silverglade, My drivers are updated and I used mostly upgraded textures. So overheating could be an issue. I just want to make sure before I go deleting my mods.

For video card temps on NVIDIA, you have to download their system tools (you just need the System Manager bit).

http://www.nvidia.com/object/nvidia_system_tools.html

Alternately, grab a copy of SpeedFan, which will show you lots of different temperatures, and is lighter on its feet.

http://www.almico.com/sfdownload.php

Video card temps vary by model as to what is "normal". There are some that are stable even up to 80C, others that run into trouble past 70C or even 60C.

The easiest way to rule out mods is to simply disable them all. It's probably the first thing I do whenever troubleshooting an issue in FO3/TES. Visual artifacts does make me want to lean toward a "hardware issue," but the fact that it only happens in certain areas and when you're facing certain directions or objects leans me back toward a "mod issue."

For your sake, it's probably easier to troubleshoot the software than your hardware at this moment. So try disabling all of your mods first and if it goes away, start re-enabling your mods maybe 5 or 10 at a time until the problem resurfaces. At this point you should have it narrowed down to a relatively small lot of mods, then just go enabling/disabling until you've found the culprit. PITA, I know.

My GPU temp is 58C. It goes into the sixties when I run Fallout 3, at least at first, and the problem occurs at least a few minutes into the game. I'm not sure if this is going to be a fixable problem anymore.
If it IS overheating, what then? If It needs more storage or RAM than I have, how do I restore some?

70C isn't half bad at all for load temperature. IIRC, a lot of cards are even happy between 80F-90F. Try going through your mods.

What should I look for though? Conflicts? What?

post deleted. Will repost in a moment.

Well the first thing you'll want to do is determine whether or not it's even a mod issue to begin with. The easiest way to do that is to disable all of your mods then run through the same portion of the game in an attempt to reproduce the issue. I realize you don't want to play the game this way, it's just for troubleshooting purposes. If you go 15-20 minutes or whatever without seeing the black bars/screen, then that would pretty much confirm it's a mod issue.

This would actually make a better flow chart, but I'll try my best in an outline format. Start with Section A below, it will set you on the right track in determining if this is an issue caused by (1) a mod file (2) modded textures/meshes or (3) possibility of hardware/driver issue.

A. Troubleshoot:

• Launch FOMM or go into Data Files, and disable all unofficial esm/esp files.
  
• Launch FO3
  
• Play around for 15-20 minutes.
  
• Did the artifacts go away?
  Yes - Mod issue, skip to Section B.
  No - Time to restore vanilla archives as well, continue to step 5.
  
• If you use Archive Invalidation Invalidated!, uninstall it. I believe you can just run the .exe file that you downloaded to undo this.
  
• IIRC, that's all you'll need to do in order to go back to the vanilla archives, but I could be wrong. You might need to rename your textures and meshes folder so FO3 doesn't seem them. You can do this by simply adding the number 1 somewhere in the file name (ex: textures1) and it will be as good as invisible to FO3.
  
• Did the artifacts go away?
  Yes - Mod issue. skip to Section C.
  No - Perhaps hardware or driver issue. My rationale- you're probably pretty close to restoring FO3 to its original unmodded state at this point, so if you're still having problems with an unmodded FO3 and it's not a global issue, then it's more likely an issue that arose from your specific configuration.

B. Mod (esm/esp) file causing issue:

• Go back into FOMM/Data Files, enable a block of 5 mods that you originally used.
  
• Launch FO3, play for 10-15 minutes.
  
• Did the artifacts go away?
  Yes - Proceed to step 4.
  No - Go back to step 1 and enable another block of 5 mods.
  
• Now that you know the problem reappeared after you enabled these one of these 5 mods, it's just a matter of narrowing it down to the culprit.
  
• Launch FOMM/Data files, disable 1 mod at a time, testing FO3 between every change. Since the glitch came back with this block of mods, you know it's probably one of these. By disabling them one at a time, you're almost guaranteed to find the mod that's causing it.

C. Texture/mesh issue:

• So the problem went away after you've returned Oblivion's archive invalidation back to its original state. This means there may be a texture or mesh (more likely, given your description) issue.
  
• Flip archive invalidation invalidated! back on, then restore your meshes folder back to its original state (remember we renamed it to "meshes1," so put it back to "meshes").
  
• For this part, I do not envy you, but you may have to go through your individual meshes folder one by one renaming them as you go along by adding a "1" to their file name. In doing so, FO3 will, once again, NOT see them and refer to the original meshes within FO3's vanilla .bsa archive.
  
• The idea is that you'll eventually come across a mesh folder that, when renamed, caused the black bars to reappear. Obviously this means that there's a mesh in this particular folder that's no bueno.

Thank you, SPARTAN VI. I'm using your troubleshoot guide.
Vanilla Fallout 3 runs exceptionally well with no lag and definitely no "artifacts." I'll start reinstalling the mods, starting with the ones that alter the worldspace.