Seaquel
SQL Server error code

SQL Server error 3102

SQL Server raises error 3102 at severity 16, which marks a problem with the query or data that you can correct.

%ls cannot process database '%ls' because it is in use by this session. It is recommended that the master database be used when performing this operation.
Msg3102
Severity16
Group3000–3999

Source: Database Engine events and errors