So yeah, I'm experiencing crashes upon saving my game. The crashes are happening at random locations when I'm trying to save, but seems to be happening more frequently when I'm close to Megaton. I'm not using autosave, since I've heard that it could mess up the game.

Also I found these errors while creating a new merged patch (deleted the skyforest mod since it was making my game crash on startup)

Errors in bold

[00:52] Background Loader: [CanterburyCommonsInteriors.esp] Building reference info.
[00:52] Background Loader: [FairfaxApartment.esp] Building reference info.
[00:52] Background Loader: Error: record TXST contains unexpected (or out of order) subrecord TX02 32305854
[00:52] Background Loader: Errors were found in: YevictexturesetDUPLICATE000 [TXST:4D001EF9]
[00:52] Background Loader: Contained subrecords: EDID OBND TX02 DNAM
[00:52] Background Loader: [CEI - CaesarrulezExcessiveInteriorsEN.esp] Building reference info.
[00:53] Background Loader: [FLAK.esp] Building reference info.

What should I do?

Post a load order from Fallout Mod Manager

It seems that FairfaxApartment mod has some errors or maybe placed in a wrong load order. I really don't know since I don't use that mod, very sorry.

Have you had a chance to watch the http://www.fallout3nexus.com/downloads/file.php?id=13111? You may find something on it that will help you with any further issues as well

Fallout3.esm
Anchorage.esm
ThePitt.esm
StreetLights.esm
BrokenSteel.esm
PointLookout.esm
Zeta.esm
CRAFT.esm
CALIBR.esm
xCALIBR.esm
Project Beauty.esm
ArefuExpandedByAzar.esm
FO3 Wanderers Edition - Main File.esm
Mart's Mutant Mod.esm
Enhanced Weather - Rain and Snow.esm
Xepha's Dynamic Weather.esm
Vehicle Overhaul.esm
DCInteriors_ComboEdition.esm
DarNifiedUIF3.esp
Project Beauty- Broken Steel.esp
Project Beauty- Point Lookout.esp
CivilDefenseBroadcastSystem.esp
Jakes Survival Shop 1-2.esp
Fast_but_dramatic_VATS_0.9.esp
playbackdelay_001.esp
TinCanCRAFTing.esp
FalloutFood.esp
Radio Active.esp
RobotRadio.esp
Faster PipBoy Light.esp
GalaxyNewsRadio100[M].esp
TheDaysofChristmasRadio.esp
ArefuExpandedByAzar-Radio.esp
Fallin3 SouthEast Wasteland.esp
RadioBlues.esp
People_Radio.esp
RadioTenpenny.esp
IPip.esp
CONELRAD 640-1240.esp
Makes Sense Bounty Hunter 0.91.esp
0rb_BookSet1.esp
0rb_ComicPack1.esp
BoSPatrols.esp
Glow Sticks.esp
FalloutFoods - FWE Master Release.esp
rockville.esp
BlackWolf Backpack.esp
BlackWolf Backpack - Vendor Script Replenish.esp
Blank's Container Backpack (BlackWolf Backpack Plugin).esp
JunkShop.esp
BlackWolf Backpack - Blank's Container Patch.esp
MaintenanceShed.esp
Solace.esp
KORsUnderwaterHome.esp
A-Vault2.esp
D.C. Confidential.esp
ShadySands.esp
CrowdedCities_v2.esp
FEV_Subjects.esp
richvendors.esp
Ex Libris - PreWar Book Titles.esp
UndergroundHideout.esp
bus.esp
Dukov_Storage.esp
DCInteriors_DLC_Collectables.esp
Rivet_City_Security_1.1.esp
Megaton Tweaks 1.28.esp
WastelandHomes.esp
GrayditchApartment.esp
Bonds Tenpenny Tower Complete.esp
AbramsOverpassTent.esp
MegatonHouseExtraStorage.esp
SuperDuperBasemant.esp
MovinOnUp3.0.esp
PeachCreekRuins.esp
Dukov3Release.esp
CanterburyCommonsInteriors.esp
FairfaxApartment.esp
CEI - CaesarrulezExcessiveInteriorsEN.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 - Alternate Travel.esp
FO3 Wanderers Edition - Followers Enhanced (BrokenSteel).esp
FO3 Wanderers Edition - Project Beauty.esp
FO3 Wanderers Edition - Project Beauty (Followers Enhanced).esp
WeaponModKits.esp
WeaponModKits - FWE Master Release.esp
WeaponModKits - OperationAnchorage.esp
WeaponModKits - ThePitt.esp
WeaponModKits - BrokenSteel.esp
WeaponModKits - PointLookout.esp
WeaponModKits - Zeta.esp
xCALIBRmunitions.esp
xCALIBRmunitions_FOSEnhancements.esp
Dogmeat Leather Armor - CRAFT.esp
Responsive Kill Reactions.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 Point Lookout.esp
Mart's Mutant Mod - DLC Zeta.esp
Mart's Mutant Mod - FWE Master Release.esp
Mart's Mutant Mod - Project Beauty + FWE.esp
Owned!.esp
I'll Touch What I Want.esp
SpeechLite.esp
Bigtown upgraded.esp
FreeBuildingV0.5.esp
Rivet_city_security.esp
Warrington Station Old Settlement and Stronghold V0.80.esp
Rington Station Settlement 0.81.esp
Fellout-pipboylight.esp
Enhanced Weather - Rain and Snow in Fallout.esp
Enhanced Weather - Radioactive Rain and Snow Plugin.esp
Enhanced Weather - Weather Sounds in Interiors.esp
Enhanced Weather - Sneak Bonus during Storms.esp
Enhanced Weather - REBOOT.esp
Fellout-Full.esp
Fellout-Anchorage.esp
Fellout-BrokenSteel.esp
Fellout-PointLookout.esp
Fellout-Zeta.esp
Realistic Interior Lighting.esp
Realistic Interior Lighting - BS.esp
Realistic Interior Lighting - OA.esp
Xepha's Dynamic Weather - Main.esp
Xepha's Dynamic Weather - Anchorage.esp
Merged.esp

Total active plugins: 134
Total plugins: 134

Move FalloutFoods - FWE Master Release.esp after FWE files.

I really don't think you can play fellout, and dynamic weather at the same time (it is ok to play enhanced weather with each of them though) so pick one

Did you grab the latest update for MMM yet (came out either yesterday or the day before)?
Weapon mod kit with FWE isn't up to date yet, but it is being worked on...it shouldn't cause the crashes though. I really can't see anything that would cause those, maybe someone else will though

Wow, thanks for that Install Guide-video. I think I'm going to uninstall everything actually and just start over again, because I've made a lot of errors I can tell now and I'm going to skip some smaller mods too I think.

fojlop, I wish you the best of luck and give you credit for your determination I know it can be overwhelming and because you are going threw all of this, you are learning, and you know what, you will be here helping other people that had the same issues as you

When you un-install, make sure you delete the fallout folders from both the program files area and the documents area, that way you have a fresh clean start.

Allright, I'm back with problems for you to solve!

I did an entire clean of my Fallout 3-stuff, so everything gone, clean start. I followed that install video and did exactly what he said, of course I had to do some adjustments since it's pretty outdated by now.
I finished my whole setup with no errors whatsoever, throwing out some mods that I realized that I didn't want afterall. Aaaand, I am still getting that damn Save - CTD. I'm posting my loadorder down here so please have a look at it and tell me if something looks totally messed up.

Fallout3.esm
Anchorage.esm
ThePitt.esm
BrokenSteel.esm
PointLookout.esm
Zeta.esm
CRAFT.esm
CALIBR.esm
xCALIBR.esm
Project Beauty.esm
ArefuExpandedByAzar.esm
StreetLights.esm
DCInteriors_ComboEdition.esm
FO3 Wanderers Edition - Main File.esm
Mart's Mutant Mod.esm
Enhanced Weather - Rain and Snow.esm
Vehicle Overhaul.esm
DarNifiedUIF3.esp
Project Beauty- Broken Steel.esp
Project Beauty- Point Lookout.esp
Faster PipBoy Light.esp
Owned!.esp
Makes Sense Bounty Hunter 0.91.esp
xCALIBRammo_FWE.esp
xCALIBRmunitions.esp
xCALIBRmunitions_FOSEnhancements.esp
Fallin3 SouthEast Wasteland.esp
DCInteriors_DLC_Collectables.esp
Rivet_City_Security_1.1.esp
CrowdedCities_v2.esp
FEV_Subjects.esp
Responsive Kill Reactions.esp
FalloutFood.esp
I'll Touch What I Want.esp
TinCanCRAFTing.esp
richvendors.esp
Ex Libris - PreWar Book Titles.esp
SpeechLite.esp
Bigtown upgraded.esp
Rington Station Settlement 0.81.esp
rockville.esp
FLAK.esp
ShadySands.esp
MovinOnUp3.0.esp
PeachCreekRuins.esp
CanterburyCommonsInteriors.esp
Megaton Tweaks 1.28.esp
WastelandHomes.esp
GrayditchApartment.esp
Solace.esp
AbramsOverpassTent.esp
MegatonHouseExtraStorage.esp
SuperDuperBasemant.esp
BlackWolf Backpack.esp
BlackWolf Backpack - Vendor Script Replenish.esp
BlackWolf Backpack - Blank's Container Patch.esp
Blank's Container Backpack (BlackWolf Backpack Plugin).esp
D.C. Confidential.esp
0rb_BookSet1.esp
0rb_ComicPack1.esp
BoSPatrols.esp
Glow Sticks.esp
CEI - CaesarrulezExcessiveInteriorsEN.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
FO3 Wanderers Edition - Alternate Travel.esp
FO3 Wanderers Edition - Project Beauty.esp
FO3 Wanderers Edition - Project Beauty (Followers Enhanced).esp
FalloutFoods - FWE Master Release.esp
WeaponModKits.esp
WeaponModKits - FWE Master Release.esp
WeaponModKits - OperationAnchorage.esp
WeaponModKits - ThePitt.esp
WeaponModKits - BrokenSteel.esp
WeaponModKits - PointLookout.esp
WeaponModKits - Zeta.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 Point Lookout.esp
Mart's Mutant Mod - DLC Zeta.esp
Mart's Mutant Mod - FWE Master Release.esp
Mart's Mutant Mod - FWE Master Release + Project Beauty.esp
Mart's Mutant Mod - FWE Master Release + DLCs.esp
Fellout-Full.esp
Fellout-BrokenSteel.esp
Fellout-pipboylight.esp
Fellout-Anchorage.esp
Fellout-Zeta.esp
Fellout-PointLookout.esp
Dogmeat Leather Armor - CRAFT.esp
Realistic Interior Lighting.esp
Realistic Interior Lighting - BS.esp
Realistic Interior Lighting - OA.esp
Realistic Interior Lighting - PL.esp
Enhanced Weather - Rain and Snow in Fallout.esp
Enhanced Weather - REBOOT.esp
Enhanced Weather - Radioactive Rain and Snow Plugin.esp
Enhanced Weather - Sneak Bonus during Storms.esp
Enhanced Weather - Weather Sounds in Interiors.esp
Merged Patch.esp

Total active plugins: 107
Total plugins: 107

Get B.O.S.S. and GaryBash. I think Fellout might be incorporated with FWE or one of the over mods you have. you may not need it.

http://www.fallout3nexus.com/downloads/file.php?id=10193 and http://fallout3nexus.com/downloads/file.php?id=11336

I'm currently getting help with this problem over at Nexus-forums aswell. These are the things I've tried without success so far:

• Installing Unofficial Fallout 3 Patch, still crashes when I'm saving.
  
• Killing myself in-game, letting the game reload and then try to save. Did this both with UF3P and without it, crashes both times.
  
• Installed http://www.fallout3nexus.com/downloads/file.php?id=3729 and letting the game save by itself, crashed after 5 minutes so I'm guessing that was when CASM was trying to save the game.
  Also tried with the manual save-function in CASM, but crashed aswell.

Does it happen on an older save? Try a save several hours older. Does it only happen once you enter a certain area? Can you save if you avoid that cell?

Yeah, it seems to be happening when I get close to Megaton.

I'll try saving on an older save later today, will get back here with the results.

I bet it is a mod that needs to be master updated. The only thing I can think of for you ( that is quick and easy ) to try is to master update everything. If you don't have FO3Edit, get it from http://www.fallout3nexus.com/downloads/file.php?id=1925 under the update section. This is a pain cause you have to re-run FO3MasterUpdate any time you install a new mod. But it should help with the crashes until you have time to find the mod that is causing this.

Actually, I've been using FO3MasterUpdate everytime I'm installing/deinstalling new or old mods.

Allright, I loaded an older save when I actually was inside Megaton. Tried to do the manual-save from CASM, which worked. I also waited for the autosave-function, which worked aswell.
I then went to Springvale Elementary to clean up the radier-pack outside of it, went back to Megaton and when I tried to manual-save when I was outside of Megaton, the game crashed as I suspected it would.

Just a couple of things. Have you used BOSS to set the load order. (http://www.fallout3nexus.com/downloads/file.php?id=10193). A couple of posts back mentioned it. It will be a long process but an alternative is to disable mods one at a time and try saving each time. When it starts to work correctly, you'll know the mod that's causing the problem.

Doug

I have now done this:

• Download + install of BOSS and Microsoft Visual C++ Runtime Library 2008.
  
• Ran BOSS-F.bat and let it rearrange my mods.
  
• Opened FOMM and rearranged the "unknown" mods, dunno if I've set 'em up perfectly though, since pretty much two thirds of my mods were "unknown" to BOSS
  
• Ran FO3MasterRestore, deactivated+deleted my Merged Patch. Ran FO3Edit, made a new merged patch and ran FO3MasterUpdate.
  
• Launched, tried the exact same thing; loading an older save when I'm inside Megaton, cleaning up raiders at Springvale and then going back to Megaton.
  When I get about 200 metres from Megaton, I try a save and then the game crashes.

My current loadorder:

Fallout3.esm
Anchorage.esm
ThePitt.esm
BrokenSteel.esm
PointLookout.esm
Zeta.esm
Unofficial Fallout 3 Patch.esm
CRAFT.esm
CALIBR.esm
xCALIBR.esm
Project Beauty.esm
StreetLights.esm
ArefuExpandedByAzar.esm
FO3 Wanderers Edition - Main File.esm
Mart's Mutant Mod.esm
Enhanced Weather - Rain and Snow.esm
Vehicle Overhaul.esm
DCInteriors_ComboEdition.esm
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
Project Beauty- Broken Steel.esp
Project Beauty- Point Lookout.esp
playbackdelay_001.esp
DarNifiedUIF3.esp
Fellout-pipboylight.esp
CASM.esp
rockville.esp
BlackWolf Backpack.esp
BlackWolf Backpack - Vendor Script Replenish.esp
BlackWolf Backpack - Blank's Container Patch.esp
Blank's Container Backpack (BlackWolf Backpack Plugin).esp
Faster PipBoy Light.esp
Makes Sense Bounty Hunter 0.91.esp
xCALIBRammo_FWE.esp
xCALIBRmunitions.esp
xCALIBRmunitions_FOSEnhancements.esp
Fallin3 SouthEast Wasteland.esp
DCInteriors_DLC_Collectables.esp
Rivet_City_Security_1.1.esp
CrowdedCities_v2.esp
FEV_Subjects.esp
FalloutFood.esp
I'll Touch What I Want.esp
Owned!.esp
Fast_but_dramatic_VATS_0.9.esp
TinCanCRAFTing.esp
richvendors.esp
Ex Libris - PreWar Book Titles.esp
SpeechLite.esp
Bigtown upgraded.esp
Rington Station Settlement 0.81.esp
FLAK.esp
MovinOnUp3.0.esp
PeachCreekRuins.esp
CanterburyCommonsInteriors.esp
Megaton Tweaks 1.28.esp
WastelandHomes.esp
GrayditchApartment.esp
Solace.esp
AbramsOverpassTent.esp
MegatonHouseExtraStorageSG.esp
SuperDuperBasemant.esp
0rb_BookSet1.esp
0rb_ComicPack1.esp
BoSPatrols.esp
Glow Sticks.esp
CEI - CaesarrulezExcessiveInteriorsEN.esp
D.C. Confidential.esp
ShadySands.esp
FO3 Wanderers Edition - Main File.esp
FO3 Wanderers Edition - DLC Anchorage.esp
FO3 Wanderers Edition - DLC Broken Steel.esp
FO3 Wanderers Edition - DLC Mothership Zeta.esp
FO3 Wanderers Edition - DLC Point Lookout.esp
FO3 Wanderers Edition - DLC The Pitt.esp
FO3 Wanderers Edition - Alternate Travel.esp
FO3 Wanderers Edition - Followers Enhanced (BrokenSteel).esp
FO3 Wanderers Edition - Project Beauty.esp
FO3 Wanderers Edition - Project Beauty (Followers Enhanced).esp
FalloutFoods - FWE Master Release.esp
WeaponModKits.esp
WeaponModKits - FWE Master Release.esp
WeaponModKits - OperationAnchorage.esp
WeaponModKits - ThePitt.esp
WeaponModKits - BrokenSteel.esp
WeaponModKits - PointLookout.esp
WeaponModKits - Zeta.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 Point Lookout.esp
Mart's Mutant Mod - DLC Zeta.esp
Mart's Mutant Mod - FWE Master Release.esp
Mart's Mutant Mod - FWE Master Release + Project Beauty.esp
Mart's Mutant Mod - FWE Master Release + DLCs.esp
Realistic Interior Lighting.esp
Realistic Interior Lighting - BS.esp
Realistic Interior Lighting - OA.esp
Realistic Interior Lighting - PL.esp
Dogmeat Leather Armor - CRAFT.esp
Fellout-Full.esp
Fellout-Anchorage.esp
Fellout-BrokenSteel.esp
Fellout-PointLookout.esp
Fellout-Zeta.esp
Enhanced Weather - Rain and Snow in Fallout.esp
Enhanced Weather - Radioactive Rain and Snow Plugin.esp
Enhanced Weather - Weather Sounds in Interiors.esp
Enhanced Weather - Sneak Bonus during Storms.esp
Enhanced Weather - REBOOT.esp
Merged Patch.esp

Total active plugins: 115
Total plugins: 115

I'd try going inside somewhere for 8 days and waiting out a respawn. If that doesn't work here's a stab in the dark: Try deactivating Crowded Cities. I couldn't leave my Megaton House with it active in one playthrough.
If that neither of those help, start deactivating mods in groups until you can save again then add them back in one at a time until you find the offending one.

Okay, I'll try that tomorrow and get back to you then since it's getting way late for trying to remain focused.
Should I just go in anywhere though, or should I wait in one of the houses in Megaton?

Inside your Megaton house is good. You want to be somewhere where there aren't NPCs or creatures (Wadsworth and your companions are fine to have around).

This actually turned out to work! I'm now able to save my game with CASM.

However I encountered another problem while playing. My sleep-level seems to be staying at 100% no matter how much I sleep.

Have you checked your installed mods against the FWE compatibility list? https://sites.google.com/site/fo3wanderersedition/compatibility-list

Ah, thanks, that's really helpful. Seems as though Fallout Foods isn't compatible with FWE.

However I did solve the sleep-problem and the save problem now so doesn't really matter.

There's a FWE patch for http://www.fallout3nexus.com/downloads/file.php?id=6338 now on its page. Glad you're able to save now!

Yeah, I noticed that so I installed that mod again.

Thanks for all the help you guys!