Seaquel
SQL Server error code

SQL Server error 3766

SQL Server raises error 3766 at severity 16, which marks a problem with the query or data that you can correct.

Cannot drop %S_MSG '%.*ls' using old 'Table.Index' syntax, use 'Index ON Table' syntax instead.
Msg3766
Severity16
Group3000–3999

Source: Database Engine events and errors