Seaquel
SQL Server error code

SQL Server error 8668

SQL Server raises error 8668 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 contains an expression on result of aggregate function or grouping column. Consider removing expression on result of aggregate function or grouping column from select list.
Msg8668
Severity16
Group8000–8999

Source: Database Engine events and errors