I had to uninstall Ignition completely from one of my sites while upgrading from 8.1.20 to 8.1.21
The reason behind this was a destructive bug found in 8.1.20. During the upgrade, I encountered error after error, that I skipped over, until I reached an issue taking an upgrade backup. With IA support, we ended up cancelling that, uninstalling Ignition and performing a fresh install of 8.1.21.
After using our latest backup, we were able to bring all back up, where we parted ways. However, looking at the databases using the MSSQL JDBC driver, we received the error in the following Knowledgebase document link:
I didn't want to get anyone else involved, so I went with Option 2. This ended up correcting the database connection issue. I just want to put this out there for anyone else that might run into the same situation.
If you're referring to TLS v1.0 and v1.1 being included in the list of disabled ciphers suites, that's not a bug but rather an intentional change in Java. The bundled version of Java that disabled TLS v1.0 and v1.1 by default has been used since Ignition 8.1.7, so I would have expected you to run into that before 8.1.21. The backups don't include Java Runtimes, so it is possible that the java security file had been modified previously. These files are also changed during upgrades so each upgrade will require you to make that change.
However, it's strongly recommend that you use TLS v1.2 if possible. What version of SQL Server are you using? Also, what's the version of the mssql jdbc driver being used? It's located in \Ignition\user-lib\jdbc. Depending on the version of SQL Server you're connecting to, you may just need to upgrade the jdbc driver.