Seaquel
SQL Server error code

SQL Server error 1941

SQL Server raises error 1941 at severity 16, which marks a problem with the query or data that you can correct.

Cannot create nonunique clustered index on view '%.*ls' because only unique clustered indexes are allowed. Consider creating unique clustered index instead.
Msg1941
Severity16
Group1000–1999

Source: Database Engine events and errors