Seaquel
SQL Server error code

SQL Server error 979

SQL Server raises error 979 at severity 14, which marks a problem with the query or data that you can correct.

The target database ('%.*ls') is in an availability group and currently does not allow read only connections. For more information about application intent, see SQL Server Books Online.
Msg979
Severity14
Group0–999

Source: Database Engine events and errors