Seaquel
SQL Server error code

SQL Server error 8660

SQL Server raises error 8660 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 select list of the view definition does not include all columns in the GROUP BY clause. Consider adding these columns to the select list.
Msg8660
Severity16
Group8000–8999

Source: Database Engine events and errors