The no reputation glitch is somthing that has happened to my main fallout new vegas save and all fractions in the game are hostile to me apart from one or two, i did nothing to make them hate me they have simply vanished off my reputation stats.

This has pretty much destroyed the game for me as I was so far into the game, and now the only real way to make progress is to shoot everybody which has ruined the game for me so has somone got a soulution for this? Or can you please fix it?

This just happened to me last night. I just finished BoS quest on Black Mountain. I put on Faction Armor (power armor) for the first time and then went to the new vagas NCR base. Both NCR & Crimson Caravan were hostile. My reputation listing was altered (Novac: Idolized, Boomers: Liked, Goodspring: liked). I had been accepted in: NCR, Great Khans, and Crimson Caravan. Liked: BoS, Vilified with Powder Gangers. Most other place were still neutral. After this happened I looked at some wikis - put some other faction armors on and that seemed to fix the rep and map listing, but the NCR and Crimson Caravan factions are still hostile. I even reloaded the newest patch... I still get shot up. This is a major quest bug that needs to be addressed.

Hey, I had a similar problem - see my post above - I was able to fix it. The trick is to "unequip" any faction armor types you have tried on. If you just switch without "unequip" then that's when the bug pops up. I tried on BoS T51 armor, after completing the BoS arc, then switched back to my other armor (no "unequip") and I had all kinds of people shooting at me. There is a bug there, but unequiping is the key.

Avizzar

ok did u know that before wearing the bos armor you must complete the quest "for the republic part 2"? Where u ask the ncr to make peace with the bos(cause it absolutely normal for the crimson caravan and the ncr to shoot to people wearing enemy's armor) and when u complete it u can wear bos armor or ncr armor with no reputation gliches
EX: if you re idolized with ncr and they see you (after they made peace with the bos) wearing the bos PA they ll just become neutral to you and if you remove the armor the stats ll just come back to idolized
hope i made myself clear bye