Seaquel
SQL Server error code

SQL Server error 6390

SQL Server raises error 6390 at severity 16, which marks a problem with the query or data that you can correct.

ALTER SCHEMA COLLECTION failed because path '%.*ls' indexed with selective XML index '%.*ls' on table '%.*ls' would be invalidated. Either the schema or the specified path should be altered so that validation does not find any mismatches.
Msg6390
Severity16
Group6000–6999

Source: Database Engine events and errors