I now have the same/similar problem (MacBook with El Capitan, Parallels 11.1.1)
- a USB Device is connected to the MAC (Fat32) and visible there. (I do not have a NTFS MAC driver installed.)
- I start the virtual machine (Parallels 11)
- while starting the machine I select Device/External Device/my_USB_drive
- When Windows is started the USB device is not connected on the MAC side anymore, and is it also gone from Device/External Device/....
I have to unplug it and replug it to link it to the virtual machine.
Why is a device always ejected when Parallels tries to "move" it from OSX to the virtual machine (and back)?
I also notice that the device, when it was mounted in the virtual machine, is ejected when the virtual machine is shutting down. It is not visible to OSX until I unplug it and replug it.
To be able to mount it in Windows I have to plug it in, when I am already logged it. It does not work on the login screen.
I think the problem was not there in the initial version 11, I just noticed it recently.
Last edited: Dec 13, 2015