UR44 dspMIXFx App won't launch in 8.5.15

I just upgraded to 8.5.15 from Cubase 6 and can’t get the UR44 app to even open!!
Keep getting error: “Cannot use USB port: it is being used by another application.”

I don’t have any other apps open except Google Chrome.

Cubase 6 the UR44 app works fine.

Any assistance will be greatly appreciated.

The problem was also that I could not get any signal into Cubase 8.5.15 from the desktop audio thru the UR44 (everything works fine in Cubase 6). I loaded latest drivers uninstalled the UR app and reinstalled the new UR44 driver and application and now I can hear the audio from the desk top and see signal levels on the Cubase 8.5.15 channel strip. Whether this was the root cause of the issue, I dunno but it’s working now.

The dspMixFX App cannot be used at the same time as Cubase - never could. It’s design for use with other DAWs and apps.