This might be related to the "lowS" fix for a transaction maleability issue. The fix "lowS" fix is in Bitcoin 0.11.1. Armory currently does not apply the "lowS" fix, so Bitcoin 0.11.1 will refuse to relay some Armory transactions.

For now you should be able to just downgrade 0.10.2 (Edit: Actually 0.11 should work too) to broadcast, however as more nodes upgrade to 0.11.1 some Armory transactions will fail to propagate through the network.

We are working on a fix, and plan to release 0.93.3 with that fix and a few others by the end of the week.