Seaquel
SQL Server error code

SQL Server error 1990

SQL Server raises error 1990 at severity 16, which marks a problem with the query or data that you can correct.

Cannot define an index on a view with ignore_dup_key index option. Remove ignore_dup_key option and verify that view definition does not allow duplicates, or do not index view.
Msg1990
Severity16
Group1000–1999

Source: Database Engine events and errors