Seaquel
SQL Server error code

SQL Server error 6836

SQL Server raises error 6836 at severity 16, which marks a problem with the query or data that you can correct.

FOR XML EXPLICIT requires attribute-centric IDREFS or NMTOKENS field '%.*ls' to precede element-centric IDREFS/NMTOKEN fields.
Msg6836
Severity16
Group6000–6999

Source: Database Engine events and errors