Seaquel
SQL Server error code

SQL Server error 1406

SQL Server raises error 1406 at severity 16, which marks a problem with the query or data that you can correct.

Unable to force service safely. Remove database mirroring and recover database "%.*ls" to gain access.
Msg1406
NameDBM_BADSTATEFORFORCESERVICE
Severity16
Group1000–1999

What it means

The SQL Server Database Engine cannot force service because the mirroring state cannot guarantee that the force service process would work correctly.

Source: Database Engine events and errors