I'm running Bitcoin Gold 15.0.1-db7b378 (64-bit) which I downloaded from https://bitcoingold.org/downloads/

I sent a transaction last night, it's been over 12 hours but my wallet still shows the transaction as

"Offline, has not been successfully broadcast yet"

and a search of the address I sent to and the transaction hash on https://btgexp.com both tell me "Search found no results"

Anyone got any suggestions?