Should have MIB1 and MIB2 folders in root together with metainfo2.txt.
FEC 0230003f should be fine. My car has something like that, and took the update without issue. This update requires 02300030 or greater.
The xml file is created by windows media player I think, and shouldn‘t cause any problems. I have one also. No valid connect anymore either, and it’s not required.
My initial thought, given you seem to have checked most everything else, would be…
a) corrupt download/unzip
b) faulty SD/USB media