Seaquel
SQL Server error code

SQL Server error 6200

SQL Server raises error 6200 at severity 16, which marks a problem with the query or data that you can correct.

Method "%ls" of type "%ls" in assembly "%.*ls" is marked as a mutator. Mutators cannot be used in the read-only portion of the query.
Msg6200
Severity16
Group6000–6999

Source: Database Engine events and errors