I got an error running this SQL (which does not happen in SSMS, it's valid server-side SQL):

https://dbfiddle.uk/ctyn15sj

Context: I was helping someone with an XML issue in DB2 and this was basically his original syntax and I was pretty sure it would work in SQL Server and it does, but it seems to me that DBFiddle is attempting to read the '' XML column and it isn't real XML, but I think it is valid to be stored in an XML column (in SQL Server, non-schema validated)

Just an FYI, not sure really a bug