Something wrong? Idiot left to shaft children (6)
I believe the answer is:
glitch
'something wrong?' is the definition.
(a computer problem)
'idiot left to shaft children' is the wordplay.
'idiot' becomes 'git'.
'left' becomes 'l' (common abbreviation).
'to shaft' means one lot of letters goes inside another (shaft can mean to stab into).
'children' becomes 'ch' (genealogical abbreviation).
'git' placed around 'l' is 'glit'.
'glit'+'ch'='GLITCH'
(Other definitions for glitch that I've seen before include "Brief failure" , "Sudden brief malfunction in electronic system" , "Fault (electronics)" , "'Bug, fault in a system (6)'" , "Computer problem" .)