I spent over 100 hours with high NCR reputation.I intended to complete the "For the republic" endgame.

The bug is that no matter what armor I wear, or how much I boost rep with quests, the NCR troops and civilians will always shoot me on sight.The rep was at idolized and dropped to neutral on its own.They are not supposed to shoot me on neutral rep so thats when I realized there was an issue here.The funny thing is that this happens on all my earlier saves now too...I tried turning off the game, re installing and just powering my way through the NCR endgame but nothing works.

The trigger for the bug seemed to be talking to Caesar.I will give details below.

Naturally I thought if I loaded an older save that would fix the problem, no luck though.I understand there is a certain point where you are locked to a faction.I was certain I was committed to NCR.I also notice that any faction that hated me seems to be passive now, but I have only tested that on the Khans and Powders.

The purpose of this post is to report the issue.I dont think there is really going to be an easy solution to this, so I dont expect anyone to be in a position to help at the moment.Any ideas from people who had similar problems are welcome.

I ran into a similar problem upon upgrading the robots and talking to Caesar. I upgraded the robots for Mr.House, but Caesar still took that as a sign of the facilitys destruction. I dont think that is a glitch, just Caesar's ignorance. But I left straight for Hoover Dam and the NCR gunned me down on sight. My reputation with them is good so I was a bit confused. I thought it was a problem with the game til i remembered i was wearing power armor, thus the NCR thought I was a Brotherhood of Steel trying to infiltrate... Needless to say I felt like an ass...

Im sure you didnt make the same stupid mistake, though try changing your current mission to something unrelated to something against the NCR. Maybe the missions for Caesar or another enemy turn the NCR against you if it is active.