Make mistake with simple task (6)

I believe the answer is:

errand

'simple task' is the definition.

'make mistake with' is the wordplay.
'make mistake' becomes 'err' (I've seen this before).
'with' becomes 'and'.
'err'+'and'='ERRAND'

(Other definitions for errand that I've seen before include "Short journey to carry message for Renard" , "Task, message" , "Short journey done for others" , "Charge - mission" , "Mission (often run)" .)

I've seen this clue in The Times.

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