Fix crack after rathole empties (7)
I believe the answer is:
resolve
'fix' is the definition.
(I've seen this before)
'crack after rathole empties' is the wordplay.
'crack' becomes 'solve' (crack can mean to solve or decipher).
'after' is a charade indicator (letters next to each other).
'empties' means to remove the middle letters (I've seen 'emptied' mean this).
'rathole' with its centre taken out is 're'.
'solve' put after 're' is 'RESOLVE'.
(Other definitions for resolve that I've seen before include "Settle (a matter)" , "Determine firmly" , "Find the solution (to)" , "split up" , "Fix" .)