Cancelled change, it stops things working (3,6)

I believe the answer is:

off switch

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'it stops things working' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'cancelled change' is the wordplay.
'cancelled' becomes 'off' (similar in meaning).
'change' becomes 'switch' (synonyms).
'off'+'switch'='OFF SWITCH'

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I've seen this clue in The Guardian.

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