REB3603

Worth a try. I thought I had opted out of beta updates and that's what the Update tab tells me, but in the Library, it's Fallout 4 [beta].

How much VRAM does your GTX 550 Ti have?

I had the same problem. I'm using a MSI Z97 mobo. My BIOS was outdated, so I flashed it. Then I found out there is a MSI specific device driver for the onboard Intel chipset. Updated the Intel chipset device drivers. Then I found out there was a MSI specific device driver for the PCI-E 3.0 network bus, so I updated it. Started Fallout 4 and it correctly picked up my NVIDIA GeForce GTX Titan X video card and set up the video parameters to Ultra. No stuttering and a stable 56-60 FPS. I suspect my problem was using a Microsoft generic PCI-E 3.0 network bus device driver. So, visit your mobo manufacturer's website and download and install any specific device for your motherboard. The PCI-E 3.0 device driver is critical. Most people think that having the latest device drivers for their video card is good enough, forgetting the video card talks to the rest of the mobo through the PCI-E 3.0 bus.

I had the same problem. I'm using a MSI Z97 mobo. My BIOS was outdated, so I flashed it. Then I found out there is a MSI specific device driver for the onboard Intel chipset. Updated the Intel chipset device drivers. Then I found out there was a MSI specific device driver for the PCI-E 3.0 network bus, so I updated it. Started Fallout 4 and it correctly picked up my NVIDIA GeForce GTX Titan X video card and set up the video parameters to Ultra. No stuttering and a stable 56-60 FPS. I suspect my problem was using a Microsoft generic PCI-E 3.0 network bus device driver. So, visit your mobo manufacturer's website and download and install any specific device for your motherboard. The PCI-E 3.0 device driver is critical. Most people think that having the latest device drivers for their video card is good enough, forgetting the video card talks to the rest of the mobo through the PCI-E 3.0 bus.

Have Steam Delete Local Content. Do a hard start of your PC (shutdown, then a power up). Then Install Fallout 4 from your Steam Library. Immediately start (Play) the game through character creation. Save and exit. Running an NVIDIA video card? How much VRAM? Fallout 4 will run on 2Gb (2048Mb) of DDR5 VRAM. 4Gb is better. Anyway, NVIDIA video card. NVIDIA Control Panel installed? Open it and go to V-SYNC in Settings. Change it to ADAPTIVE! Using GeForce Experience? If not, d/l and install it. Then add Fallout 4 to the game list. Click optimize. This configures the NVIDIA video card. Now, go to DevENB.com and d/l ENBoost 282 for Fallout 4. Extract the two DLL files and ENBlocal.ini to the Fallout 4 root (where Fallout4.exe is located). Launch the game from Steam and enjoy.

Gameranx.com seems to have the most comprehensive list

I have two rigs, pretty much spec'ed out: ASUS Maximus GENE VI mobo; Intel i7 @ 3Ghz; 16GB DDR3 RAM; MyDigital 256GB SSD for Win7/64; 3x hybrid 1TB SATA drives; 1KW PSU; forced air cooling. One rig has a single R9 270X and the second has a single R9 290X, both with 3GB of DDR5 VRAM Frankly, I can see any difference. I have a second 270X and 290X that I use in a X-Fire config. Didn't see muich differenece there either. With a single R9, FPS rarely (!!!!) drops below 60fps. Also approaching 250 mods. Wonder what happens when I hit number 255? Why two nearly identical rigs? One is for my son, who will be returning from The Box in April and will pick it up then.

Launch Steam. Go to <Library>. Right click on The Elder Scrolls V: Skyrim. From the drop down menu, left click on Delete Local Content. When Steam tells you the local content has been deleted, close Steam, then close I.E. Do a soft restart of Windows. When Windows is fully loaded, open I.E., run Steam. In your Library, The Elder Scrolls V: Skyrim will still be listed, but grayed out. INSTALL should be right next to the name. Left click and wait patiently for Steam to re-install the local content on your PC. When the local content has finished installing, left click the "PLAY" button to insure the game will launch. Create a folder on your desktop and name it SKSE. Download the latest STABLE version (the Alpha version, NOT the beta version) of SKSE from SKSE.Silverlock.org. Move the downloaded file from Downloads to the SKSE folder on your desktop. Double-click on the file and it will extract into the SKSE folder. Open the SKSE folder, Select All and do a {Ctrl C} (Copy) and paste the contents of the SKSE folder in <?:>...\Steam\SteamApps\common\Skyrim. Remember, Steam must be running BEFORE you launch skse_loader.exe!

This happened to me a couple of years ago. I solved it by having Steam delete TES: Skyrim from my PC. Then I re-started my PC, started I.E., launched Steam, and had Stream re-install TES: Skyrim. Install SKSE in <?:>...\Steam\SteamApps\common\Skyrim Create a shortcut on your desktop to skse_loader.exe. Use this shortcut to launch Skyrim; HOWEVER, Steam HAS TO BE running BEFORE you run skse_loader! It doesn't matter where you install Nexus Mod Manager. I have mine installed in <?:>\Program Files. I think that's the default anyway. NMM will create it's own folder there and in My Documents. Use NMM <Settings> to tell it where to keep downloaded mods.

Master File Table (MFT) failed. Not recoverable. Had about a dozen Skyrim mods that I had failed to d/l the 7zip file as a backup. Found all but one. Dwarven Fortress on an island west of either Windhelm or Solitude. There was a boat you could take to the island fortress. Fortress was borderline between large and huge. Unoccupied. Dungeon, of course. Lots of places to discover and explore. Anyone who knows the mod number and could get it to me would help me out a lot.

Server's still not allowing NMM to log me in.

Device driver issue. Download the most recent NVIDIA device driver package and install it, even if you updated the drivers after you installed the card. Sometimes, not all the drivers get registered in the Registry. NVIDIA drivers are notorious for this unless they are "genuine" NVIDIA drivers.

Sigh. Sometimes, you have to step backwards to move forwards. There is a version registration issue with most of Bethesda's FONV files (including .bsa files). BSA Unpacker from early in 2006 (yeah, six years ago) will overlook the version registration issues to unpack and extract .bsa files. I also found a neat .dds thumbnail viewer (freeware), but can't find the sticky note on which I wrote the link. I will post the link when I find it.

Ouch! Hope you are also stopping all unnecessary applications and processes from the Task Manager AND running fnv4gb.exe! Your mod list puts you right on the cusp of Bethesda's required RAM and virtual RAM needed to run the game. Looks like you might have 200-250Mb of free memory available. Not nearly enough. The crashes are occurring when the game has to swap out game code in RAM for game code in virtual RAM. Also, there is a cool 3rd party gadget that tracks RAM and virtual RAM usage and only uses 4Kb of RAM! I think there is a link to it from the Gadget Side Bar (must be running Windows Vista/7/8).

Sigh. I need help. I have BSA Commander and BSA Unpacker. Latest version of Java Runtime was downloaded Thursday night (3/28/13). They work just fine with TES: Oblivion, FO3, and SkyRim. FONV just doesn't want to play nice and I need to get into a .bsa file to edit some textures. I can open the archive in a good text editor, but I really have neither the time, nor the patience to edit textures using text strings.

BOSS has sort load order issues with where it places some .esp files in relation to others. You can also try moving the five PROJECT NEVADA .esp files to the tail end of your load order. If you later add FOOKNV, put FOOKNV.esp and FOOKNV_DLC.esp dead last, it that order. Worked for me.

Retail or Steam version? If Steam version, I found this works: install NMM; set up a custom launcher using just "fnv4gb" with no arguments. If Steam isn't running, launch Steam. Then launch NMM. Left click on NMM's custom launcher button. Be sure you're using nvse 1.4. It has nvse_steam_loader.dll. Earlier versions do not. When Steam is told to launch FNV, it uses that DLL to launch NVSE.