Made an error on record -- this brings back discomfort (7,4)
I believe the answer is:
slipped disc
'this brings back discomfort' is the definition.
The definition suggests a singular noun which matches the answer.
'made an error on record' is the wordplay.
'made an error' becomes 'slipped' (I've seen this before).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'record' becomes 'disc' (eg a CD, compact disc).
'slipped'+'disc'='SLIPPED DISC'
Can you help me to learn more?
(Other definitions for slipped disc that I've seen before include "column's piece being misplaced" , "Spinal ailment" , "Cause of back trouble" , "Spinal problem" , "Painful back problem" .)