Can't copy folder to a passthrough USB device

[TheVMinator]

I have a USB drive connected to my ESXi 5.1 host and configured such that my Windows 2008 Enterprise Server R2 VM recognizes it as a local USB device.

I can see and open the USB device in Windows and even copy a few files to it.  but after about 60 seconds it freezes up on this window and doesn't go any further.  I attached a screenshot showing the screen it is frozen on.
How can I troubleshoot why I can't copy this folder to my USB device?  I can copy files to other VMs, NAS locations, to the internet, etc. but can't copy to this USB drive even though it has 900 GB free and I only have 100 GB to copy.

Any ideas?

[TommyFreddy]

I have the similar problems. Can't solve ..

Take care!

[TheVMinator]

Actually I retried this and let it run for a long time.  After about 10-20 minutes it finally got past that screen.  Eventually it finished copying 100 GB after maybe 4 hours