I was exploring around Armory in Expert mode and noticed an issue when I clicked on the "Broadcast Raw Transaction" option - a window popped up saying "Bitcoin Core is not online, Armory will not be able to broadcast a transaction". But my main dashboard says "Armory is Online!", and the bottom right hand corner of Armory say "Connected" with the current block number and counting, new block count shows successfully; and any transaction that I send to my wallet shows as confirmed.
Just ignore it... I get the same thing. Main dashboard says "online" and shows connected with blocks etc, but the "Broadcast Raw Transaction" option says "Bitcoin Core is not online..." etc.
All that does is allow you to manually broadcast a "raw" transaction (which you can do actually do from Bitcoin Core using
sendrawtransaction)... it isn't related to creating/signing/broadcasting transaction using an Offline/Online airgap setup and the "Offline Transactions" button.
https://i.imgur.com/ePDYlwf.png