Fix 'Err' (error) message on Goodmans VN9500S VCR?

Goodmans VN9500S VCR will tune into tele progs but when tape is inserted it will load but not play, rewind, fast forward etc but shows 'Err' on display. When any button is then pressed it will either remove tape from head or eject the tape. Have looked inside to see if anything obvious needs sorting but nothing apparant. All leads & scart leads are connected properly. Operating manual has nothing about this problem. Any suggestions?