MarcT77 said:
Just found this tool http://www.ridgecrop.demon.co.uk/index.htm?guiformat.ht... which formatted the card without issue
I just registered to say: thanks bro!! that worked perfectly, not even ten seconds, and my obscure brand 64gb exFat micro sd card was formatted to fat32. thank you!!
UPDATE:
Sorry, a follow-up: the conversion tool worked fine as I said before, but it turned out that my Micro SD Card was a fake / defective.
I found a program called H2TestW (google it) to check the card, which takes a long time to finish (2.5 hours!), but confirmed that my 64GB card was actually only 4GB (and defective at that!).
So to others who have perhaps also bought a cheap Micro SD Card off eBay, it is worth first checking whether your card is a fake, before you start copying all your data and eventually lose all of it!