Setter’s visas having insuperable problems (8)
I believe the answer is:
impasses
'insuperable problems' is the definition.
'setter's visas' is the wordplay.
'setter's' becomes 'im' (I've seen this in other clues).
'visas' becomes 'passes'.
'im'+'passes'='IMPASSES'
'having' acts as a link.
(Other definitions for impasses that I've seen before include "Deadlocks, stand-offs" , "Deadlocks, stalemates" .)