When updating to the latest ESE agent version (22.04.11.18121), a warning "Could not connect to database server" presents:
This happens because the SQL database that is running the SIMS instance is still using an earlier TLS protocol (e.g. 1.0 or 1.1), most likely as a result of the system's Microsoft updates not being up to date. For security purposes, Redstor no longer supports connections other than TLS 1.2 for communication between the ESE agent and the SIMS application. If the underlying SQL does not allow higher TLS versions, the agent will not be able to communicate with SIMS.
Install the latest Microsoft updates. This may involve a SQL update and/or a .NET Framework update, as outlined by Microsoft here.
If you are unable to update, you can alternatively use VSS backups of the SQL database and the SIMS shared directory, and DocStorage folders via the Files view in ESE. This will protect the same data, although the Data Selected figure may be slightly higher because the VSS backup does not compress the database as thoroughly.