Seaquel
SQL Server error code

SQL Server error 1421

SQL Server raises error 1421 at severity 16, which marks a problem with the query or data that you can correct.

Communications to the remote server instance '%.*ls' failed to complete before its timeout. The ALTER DATABASE command may have not completed. Retry the command.
Msg1421
Severity16
Group1000–1999

Source: Database Engine events and errors