Like Theberge43, I have no Firewall.log file.
Attached is a copy of the C:\ProgramData\AVAST Software\Avast\log\Setup.log file.
I reinstalled the SOA Console (1.3.3.89) on the Windows 2012r2 server and rebooted. I confirmed the SOA was there using an IE browser on a Windows 10 client PC, logging on.
I then ran avastclear.exe on the Windows 10 PC, removing the Avast! Free Security program. Rebooted and then installed the EPSP standalone client program (8.0.1606.511), rebooting three times. The firewall never installs.