No Item In This Directory error

An hour or so into working on the big cnc and loading up various tool paths, it stopped reading my USB (1GB) and now displays “There is no item in this directory” whenever I try to access UDisk File. Tried on 3 other small drives, tried formatting drives to various specs as cnc forums suggested but no luck. Any ideas?

I’m midway through a project so trying to avoid a reboot as much as possible, but may be my only option.

Ended up resolving via reboot. Not sure what caused it in the first place though.