Hello all

UMM ..well am to the part where u have to talk to the NCR and they just keep killing me when i walk over there, y? help thanks..

Who keeps killing you the Kings? or the NCR? When do they start killing?

Are you wearing faction armor?

Noo am not weaning faction armor..and the NCR are killing me when the kings tell you to help pacer..

Ah now its more clear, you didn't do the optional parts of the quest thus the diplomatic solution is impossible.
Or you walked up with a weapon drawn.