it was working alright until today i turned my D80 on to try out some shots. FE E shows, i tried to take it out and put it back on but it still gives the same error, but nothing wrong with my other kit lens
Look at the aperture ring on the 50mm.
if it is not at f22, the error will appear as the aperture is adjusted through the camera and not at the lens.
To solve the problem, just turn it to f22 and lock it so you won't accidently turn it again.