Problem having no opening to make money (6)
I believe the answer is:
rouble
'money' is the definition.
(I've seen this before)
'problem having no opening to' is the wordplay.
'problem' becomes 'rub' (the rub can mean a problem or catch).
'having' is an insertion indicator.
'no' becomes 'O' (O resembles 0).
'opening to' becomes 'le' (I am not sure about this - if you are sure you should believe this answer much more).
'rub' going around 'o' is 'roub'.
'roub'+'le'='ROUBLE'
'make' acts as a link.
Can you help me to learn more?
(Other definitions for rouble that I've seen before include "bread from abroad" , "foreign currency" , "9 Across currency" , "Russian bread" , "Russian currency unit" .)