Complication no good in story (6)
I believe the answer is:
tangle
'complication' is the definition.
('tangle' can be a synonym of 'complication')
'no good in story' is the wordplay.
'no' becomes 'n' (common abbreviation).
'good' becomes 'g' (abbreviation).
'in' means one lot of letters goes inside another.
'story' becomes 'tale' ('tale' can be a synonym of 'story').
'n'+'g'='ng'
'ng' inserted into 'tale' is 'TANGLE'.
(Other definitions for tangle that I've seen before include "Complication" , "coarse seaweed" , "Confused mess" , "Trap < tall guy from Perth" , "Twist into a confused mass, or informally fight with" .)