I tried multiple file systems and multiple devices, none of them will mount. I also tried looking for
fsck (not running), resetting the NVRAM (and restarting the Mac of course) and it still doesn't work. It shows up correctly in the Disk Utility, however it stays unmounted (even if I click mount). Is there anything else I can do? What might be wrong? FYI I did check the following thread (although my problem is a bit different) and tried these solutions, didn't work.
UPDATE As requested by the comment, I ran the following:
diskutil list disk2 /dev/disk2 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: ClickShare *23.5 MB disk2