For the issue we had with someone who had Compliance v.1.10 on Server 2012 R2, they restored the Compliance server and its database from backups done just before they started the upgrade. They ran the upgrade fixlet a second time and it worked, so I am not sure what happened there and we closed the case with IBM.
On our installation on Server 2016 that I started the thread for, it was related to TLS settings. In Compliance in the Server Settings it was set to use TLS 1.2, and I found that if I unchecked that then Compliance would work.
Looking at the server I found that TLS 1.0 and 1.1 were disabled but TLS 1.2 was not working correctly even though it was enabled in SQL. Once we got the TLS 1.2 settings working Compliance continued to work with the setting checked.