Fairly new to Armory and I'm just testing things out sending a small amount between wallets just to learn. I broadcast one transaction with success, but the second one keeps failing.
So I create the transaction in online armory and sign it on offline computer. Load the signed transaction on the online and it says "All Signatures Valid!" Armory shows "Connected 309XXX Blocks", but when go to broadcast I get a taskbar error message pop up saying something like "Connection to BitcoinQT Lost, Armory can't send the transaction until you reconnect" and then it says "Connection to Bitcoin QT re-established" and it does this a couple of times. Finally I get a pop up window in Armory saying "Invalid Transaction - Transaction not accepted by the bitcoin network, due to a bug with Armory..."
I've restarted Armory a couple of times and tried broadcasting a number of times to no avail. Again this is the second transaction I am trying, the first went off without a hitch, so I'm not sure what the issue could be. Any thoughts would be much appreciated!
Did you create the two transactions at the same time? It's possible that the first transaction turned out to be a double spend of the second-- this happens because Armory doesn't keep track of what outputs have
potentially already been spent when creating a new transaction, unless that transactions is broadcast already. This would match your symptoms, too: Bitcoin Core sees you broadcast a tx spending inputs that have already been spent, flags you as misbehaving and disconnects you. You can be sure about it by looking the Bitcoin Core logs... it usually tells you why it disconnected. Or simply create a new offline transaction, sign and broadcast. As long as the previous one has been broadcast by the time you create the next, everything will be fine.