Ignited fire inside grand church, creating a problem (6)
I believe the answer is:
glitch
'a problem' is the definition.
(a glitch is a problem or malfunction)
'ignited fire inside grand church' is the wordplay.
'ignited fire' becomes 'lit' (I can't justify this - if you can you should believe this answer much more).
'inside' means one lot of letters goes inside another.
'grand' becomes 'g' (G is short for grand as in a thousand).
'church' becomes 'ch' (common abbreviation).
'g'+'ch'='gch'
'lit' placed inside 'gch' is 'GLITCH'.
'creating' is the link.
Can you help me to learn more?
(Other definitions for glitch that I've seen before include "Fault (electronics)" , "Temporary fault" , "Find fault" , "Brief failure" , "An informal malfunction" .)