I don't know how that's possible -- the BS plugin edits just two creature entries (Deathclaws) and five levelled lists, mostly wasteland spawns.
tried it again, and it is a MMM plugin causing it, with the plugins on, i get to the end and fawkes gives me the same reason as before for not wanting to go into the room, and if i or sarah go in and input the code its gameover and credits, disabling all the MMM esp's and esm's and i can progress fine into broken steel, and can even get fawkes to go in.
Im not sure which MMM plugin is causing it, i just assumed it was the broken steel one, but disabling MMM fully allows me to continue.
my load order is as follows:
Fallout3.esm
HairTradeV1.esp
NightvisionGoggles(Powered).esp
MiscWeightFix.esp
Enhanced Weather - Radioactive Rain Plugin.esp
MrSlackPants-DecentPipBoyLight.esp
LongerDeathCamera.esp
Cats Paw.esp
PowerArmorImproved.esp
NippersArmorNips.esp
Phalanx-Obedient-Dogmeat.esp
FollowersRelax.esp
NippersWeaponNips.esp
LightweightFoodSanitizer.esp
KarmaRevamp1009.esp
BetterDrugs.esp
Classic Sniper Rifles.esp
MrSlackPants-Radiation.esp
GNR40MoreFromThe40s.esp
MissingUniqueWeapons-Enhanced.esp
F3UmpaAnimation.esp
Slower Levelling - slower.esp
Classic Lever Rifles.esp
AutoAim_6000_v1.0.esp
SmokableCigarettes.esp
40More_Part2.esp
TribalT51bHelmet.esp
repair.esp
[UU] Unique Uniques .04.esp
doctorli_glasses.esp
Roleplayable Professions.esp
UPP - Beverage Perks.esp
Inebriation.esp
AmplifiedCrippledEffectsV1-3.esp
Light_reduction.esp
Item Descriptions Img.esp
RadioBlues.esp
bittercup_comp.esp
GhostRadio.esp
MoreMapMarkers.esp
Aviators.esp
Underworld Underground.esp
Prototype Laser Mod.esp
MissingUniqueArmorClothing-Enhanced.esp
SeducingWomen.esp
YearlingsGlasses.esp
UPP - Pack 1.esp
UPP - Original Perks.esp
UPP - Quest Perks.esp
UPP - Experience Perks.esp
UPP - Pack 2.esp
FollowersHire_ByCharisma.esp
P94 Plasma Rifle.esp
GasMask.esp
Wattz Laser Weapons Mod.esp
BunkMod - Megaton House - v0.01.001.esp
CreaturePoses.esp
SomePoses.esp
wastelanderoutfit.esp
PittRepair.esp
AnchoRepair.esp
Explosive Explosives v1.3.esp
PairPoses.esp
Improved Anchorage Rewards.esp
Trophies - Megaton.esp
FO 1 and 2Combat Armor.esp
Classic Fallout Weapons BETA.esp
[CLO]BlackWolf Backpack.esp
D.C. Confidential.esp
GlobalTravelSystem.esm
GTS - The Pitt.esp
Fallout 1+2 All Locations.esp
Existence2.0.esp
Mart's Mutant Mod.esm
Mart's Mutant Mod.esp
Mart's Mutant Mod - Increased Spawns.esp
Mart's Mutant Mod - Natural Selection.esp
Mart's Mutant Mod - Hunting & Looting.esp
Mart's Mutant Mod - Tougher Traders.esp
Mart's Mutant Mod - Zones Respawn.esp
Mart's Mutant Mod - No Corpse Flies.esp
Mart's Mutant Mod - Broken Steel.esp
DarNifiedUIF3.esp
Total active plugins: 83
Total plugins: 194