TSQL (2014) - Importing XML with accented and punctuation Characters
The XML you have is invalid in UTF-8 encoding. The accented characters needs to be encoded. For instance ° should be encoded as Â°.

Here is a shorter version that also fails.

declare @X xml = '&lt;?xml version="1.0" encoding="UTF-8"?&gt;°';
select @X.value('text()[1]', 'nchar(1)');



  Msg 9420, Level 16, State 1, Line 1 XML parsing: line 1, character 39,
  illegal xml character


Should be like this instead if you use UTF-8.

declare @X xml = '&lt;?xml version="1.0" encoding="UTF-8"?&gt;Â°';
select @X.value('text()[1]', 'nchar(1)');


You need to trace the source of the data backwards to the producer to see where you end up with invalid XML.