As you could have confirmed if you tried opening the EXE.XML file with MS Edge, your EXE.XML IS corrupted (not that I wasn't sure about it), so the FSDT installer correctly labeled as such. The error is in the last sections, after the AFC Bridge lines, there's an extra line that shouldn't be there at line 27:
</SimBase.Document>
So it must be removed, because this is the final closing tag of the file, so there must be only one, at the end.