Copy to exFAT flash drive: directory cannot be created?

[Hawaiianlungs]

I have a PC with lots of RAM and Hard Disc Space. TC Version 8.51a

I am trying to copy a folder with mp4 files to a flash drive formatted with exFAT, but get an error with TC that directory cannot be created.

If I stay with "C" drive, no problem.
What should I do?

[MVV]

Does Explorer copy files to that drive?

[ghisler(Author)]

Is this in the root of the drive? If yes, does it work after you delete a file in the root?