The Ubuntu 16 LTS build instructions you provided don't work from a fresh install, even after an update/upgrade. Also, the tar you provided won't run 2ACoind. "Illegal instruction (core dumped)."
The 2ACoin.exe found within the Windows zip file is returning, repeatedly:
2018-Aug-01 23:20:04.457837 INFO [94.244.156.69:52113 INC] Your 2ACoin node is syncing with the network. You are 1246 blocks (1 days) behind the Network. Please be patient!
2018-Aug-01 23:20:04.887497 ERROR [94.244.156.69:52113 INC] Failed to handle NOTIFY_REQUEST_CHAIN. block_ids doesn't end with genesis block ID
Try them all using your instructions and you'll see what I mean.
What, if anything, works in order to mine this coin?
We just tested our instructions we provided here for Linux;
https://www.2acoin.org/software/
These instructions worked on Ubuntu 16.04 just as written.
Again, if you have further issues please feel free to ask for help on
https://chat.2acoin.org