Anyone seen this before? Im trying to flash a new FC, but it refuses to go into DFU mode, so I tried ImpulseRC driver fixer as suggested by Oscar's post:
https://oscarliang.com/fc-driver-issues-flash-firmware/

After I have it connected for a while it disconnects and I get an error stating "An error occurred while entering bootloader, Unexpected number of devices detected".

Any idea guys?

Plug the FC directly into the PC instead of using a USB hub.

If no help, try unpluging other devices that may have STM32 chips in them. I had this exact problem before. The fix for me was to unplug the frsky rx from the fc board.