Seaquel
SQL Server error code

SQL Server error 6918

SQL Server raises error 6918 at severity 16, which marks a problem with the query or data that you can correct.

XML Validation: Element '%s' must not have character or element children, because xsi:nil was set to true. %S_MSG %s
Msg6918
Severity16
Group6000–6999

Source: Database Engine events and errors