Seaquel
SQL Server error code

SQL Server error 8662

SQL Server raises error 8662 at severity 16, which marks a problem with the query or data that you can correct.

Cannot create the clustered index "%.*ls" on view "%.*ls" because the view references an unknown value (SUM aggregate of nullable expression). Consider referencing only non-nullable values in SUM. ISNULL() may be useful for this.
Msg8662
Severity16
Group8000–8999

Source: Database Engine events and errors