Also, Armory won't prepare databases unless you allow bitcoin-qt.exe, ArmoryQt.exe, and ArmoryDB.exe access through any firewall setup you may have (including Windows).

Firstly, apologies to crashtest22 et al...I didn't intend to threadjack this convo.

That being said, I also got my setup to work as well. I tried many things, and wouldn't know what fixed the issue had I not been able to compare what I did against your list. By combining our lists, it seems that the way to fix this (for me) was to upgrade to latest version of Armory, delete the database folder in bitcoin core, run bitcoin core and let it re-update (mine took the better part of a day), and then run Armory.

Everything's back to normal. Thanks to all who responded!

The .deb for 0.96.4 RC2 is labeled 0.96.3.991...unless there is an even more recent version?

I'm having the same problem with "Send Bitcoin" button not working On Ubuntu 16.04, except that my problem happened out of the blue on a fully functioning copy of Armory (96.2)...Made one successful transfer, then tried to make another to a different wallet and the button doesn't respond. Core v0.15.1 is fully synced and I even uninstalled and upgraded to Armory 0.96.3.991. No change in behavior.

I don't know if this will apply to you, but I've noticed that after having moved the blockchain data to another drive that my system can't seem to find the folder on the drive. But if I manually search for the blockchain location (using file explorer in your case) and then drill down from the drive level to the folder containing the blockchain, my system seems to "catch up" and recognise that the folder does actually exist. Hope this helps.

FWIW, I'm having the same sort of problem on Ubuntu- I'm not receiving TXs that show up on the blockchain. Only thing that seems to work is to wipe out and rebuild the database, and even then it is back to the same issue again in short order.