Seaquel
SQL Server error code

SQL Server error 1475

SQL Server raises error 1475 at severity 16, which marks a problem with the query or data that you can correct.

Database "%.*ls" might contain bulk logged changes that have not been backed up. Take a log backup on the principal database or primary database. Then restore this backup either on the mirror database to enable database mirroring or on every secondary database to enable you to join it to the availability group.
Msg1475
Severity16
Group1000–1999

Source: Database Engine events and errors