Upgrading the firmware on your GS-911 interface requires the USB connection the be reinitialised during the process. This might cause problems when doing the upgrade on a virtual Windows machine.
Here’s what to look out for:
The guest Windows machine needs to connect to “Hex Microsystems” USB devices automatically, otherwise, the upgrade will fail. The automatic USB connection should only filter on the “Hex Microsystems” Vendor ID, and Product ID, as the interface will connect in a different capacity during the upgrade procedure. Any connections to lower-level USB hardware/hubs should not be forwarded to the guest machine as this may delay the USB initialisation which will cause the upgrade to fail.