Seaquel
SQL Server error code

SQL Server error 6364

SQL Server raises error 6364 at severity 16, which marks a problem with the query or data that you can correct.

ALTER SCHEMA COLLECTION failed. Revalidation of XML columns in table '%.*ls' did not succeed due to the following reason: '%.*ls'. Either the schema or the specified data should be altered so that validation does not find any mismatches.
Msg6364
Severity16
Group6000–6999

Source: Database Engine events and errors