I call it the Big red blucko triangle... lulz It's a error, which means there is a missing mesh, a mesh is the 3D shape of something. No archive invalidation huh? Download the 1.7 patch from either Nexus, or the official bethesda fallout 3 website, then run it, even running 1.7 patch on something that is 1.7 already can fix issues sometimes, which is why I mentioned it. Next download FOMM (fallout mod manager) Then download FOSE (Fallout Script Extender) These get installed to your fallout 3 folder, as in C:/Bethesda Softworks/fallout 3. Mods get installed to C:/Bethesda Softworks/Fallout 3/Data. FOMM will allow you to create a load order, which pretty much starts with Fallout.esm, then DLC, then any mods .Esm, then any mods .Esp, and merge patch or overrides at the end. Also FOMM will launch the game from now on, via FOSE if it detects that it is installed, then FOSE will disable GFWL (games for windows live) just as a bonus as it's primary design is to allow player made scripts, which are things that allow us to do things which are ilegal like for example smoke cigarettes or be a prostitute, plus have many cool parts of mods controled thru the heads up display, among other things. Once you have FOMM an FOSE installed, launch FOMM then press the toggle Archive invalidation button. Might as well see if your big red blucko's are still there? UF3P is a nice mod, it's not a patch by any means though. It's not what is making your game run smoothly if that was what you were thinking. It's nice and I use it, but sometimes I make installs without it. I can't really even tell when it's installed or not, as it deals mostly with issues that Bethesda ignored in the patches, stuff like glitches or bugs or silly stuff. That being said you would have a lot more fun with using a bunch of tiny mods, or heck FWE or FOOK for example. But Don't use more than one of these large mods like FOOK2, FWE, UF3P. Well not until you know what you are doing. It's more of a learning process than anything else. You make tons of mistakes, then maybe you learn a bit for next time. The load order I'm currently using I spent over 50 hours just fixing it to all work together as to avoid issues, thus getting the 4-8 hour long games without crashing or having problems while using 150 mods. Once I figured out how to do that I could pretty much do anything I could think up in the game world. I'll probalby play a vanilla game the next time I re-install fallout to make a new build. Stuff you want to look into as far as mods there's a whole lot of great mods out there. All the DLC's are totaly worth it. Groovatron Umpa animation (Groovatron has many tools as well as working the umpa animations an more fully into the game) MMM marts mutant mod (Pure magic is what Mart does, besides reskining every creature it also adds new ones, an can increase the spawns as much as you want in my version those 3 NPC's you saw turned into 18-21) Bullet time (hotkey controled bullet time) Real injuries primary needs (Get shot then you bleed out, more realistic injury, plus primay needs adds the need to sleep, eat, drink) More precise auto aim (gets rid of autoaim bugs, but doesn't disable it, as to provide support for all weapons in both 1st person an 3rd person views) VATS MCE (makes VATS actually work well for a change, this bases chance to hit in VATS off weapon skill) VATS at longer distances (makes it so you can VATS further than 2 feet away, think sniper VATS) Ultimate perk pack (10,000 funny an useful, to totaly awesome perks you can take when you level up) 20th century weapons (Modular an 100% clean version of 10,000 modern weapons) FOOK 2 (Just like 20th cenutry weapons but it's goes in a more complex path to overhawl the entire fallout 3 game) FWE fallout wanders edtion (Just like FOOK an 20th century weapons only it deals with game settings very heavy) Fellout (gets rid of the green looking game world, makes it look real, also controls climate) Enhanced weather Rain an snow (adds rain an snow to the wasteland) Talior made ( takes bits an parts off armors an makes it so you can wear just that part, thus more options with your armor) D.C interiors project (got to luv chuck, he redid most of the downtown area only now you can go in just about all the buildings) RR companions vault ( a huge vault, which also has a entirely new companion system built in to it, with other players making tons of companions) Project beauty HD (Change the faces of every NPC in the game making them look better or worse in a HD way) Lings (adds stuff to be able to create more different looking charicters, mostly a merger of that type stuff) Lings finer things (merger of all the awesome clothing based off player made nude bodies) animated prostitution (be a hooker if you want or be a pimp, sleep with NPC's in a nasty sexual way, Gee I make it sound so dirty huh, it's fun) Usable cigarettes (this place is aweful, that guy's head just exploded, I need a smoke, besides got to do something with all the loot.) Inebriation (Get balls drunk, can't walk straght, an the screen blurs if you take a drink) BLTC better living thru chems (kind of a dirty mod, but fun, it adds real world drugs, fun I guess, it's messy, so might cause problems if you use it with other mods) GTS global travel system (travel the globe) Slaves stick around ( enslave anyone, an they get sent to the slave pin rather than disapear) Calibr and Xcalibr (adds real world ammo, Xcalibr adds a shop an makes the world models of the ammo look totaly awesome) Enclave commander ( Vertibird control, drop a strike squad in any area, either enclave, BOS, or outcast, with many types of NPC's, tanks, missle attacks, minigun, fire bomb or nuke targets) Streetlights (adds streetlights to the DC area) EVE- Energy visuals enhanced (makes energy weapons totally friggan awesome) GNR-100 more where that came fromz (adds 100 ole timer songs to the GNR station plus old bethesda comercials) KABOOM (makes explosions better) LessBouncyGrenades (frags don't wander off so much) TalonExtraArmor (makes Talon company pure Bad A**es) DarNified UIF3 (makes the user interface in fallout 3 not suck ballz)