I'm also having the build database error on 0.95.1 with Core 0.13.1 on Ubuntu. I have killed bitcoind, and closed Armory (there was no ArmoryDB running in Ubuntu). I start bitcoind first and then run Armory, but Armory complains that Core is running and I must shut it down. I assumed this was because I didn't have an RPC username and password, but the bitcoin.conf is empty and armory doesn't seem to be creating it as usual.
However, once I kill bitcoind and have armory check again it runs and gets the Build Database error. I did run armory from terminal and this error seems to keep repeating which is why it's not going anywhere:
(ERROR) SDM.py:791 - ValueError in bkgd req top blk
Traceback (most recent call last):
File "/usr/lib/armory/SDM.py", line 765, in __backgroundRequestTopBlock
numblks = self.proxy.getinfo()['blocks']
File "/usr/lib/armory/bitcoinrpc_jsonrpc/authproxy.py", line 105, in __call__
resp = json.loads(resp, parse_float=decimal.Decimal)
File "/usr/lib/python2.7/json/__init__.py", line 352, in loads
return cls(encoding=encoding, **kw).decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 364, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 382, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded
A couple things - after a full factory reset of Armory it doesn't create the bitcoin.conf file with the RPC codes. Had it stopped doing that in recent updates? Does Armory require Python 3?