Official comment
Sounds like you're possibly using an older version of Windows which wasn't fully updated to include the current driver certificate signatures. Uninstall the driver, disconnect the mixer, fully update windows and apply all service packs, then reboot. Install the drivers by right-clicking and running the installer in administrative mode, reboot again.
If you still have issues, you may need to bypass the driver signing, but that can be an issue every time you restart your computer.