Cannot use usb port, it is being used by another application

I just got the UR44 and am trying to get everything to work.

I would like to use the UR44 mixer for zero latency Bud when I start Cubase 8AI up, the mixer greys out and the following message appears: “Cannot use USB port, it is being used by another application”.

It is working fine when I am using Cubase 5 LE.

Can anyone tell me what to do?

Best regards


The UR44 has integration with later Cubase versions. You control everything from inside of Cubase and dspmix is disabled. Unfortunately this does put some limitations on how you can work with it.
You can still select direct monitoring in Cubase device setup for zero latency but I think this only works when in record so you can’t permanently monitor your inputs as you can using dspmix…works OK for example for recording vocals or guitar, but useless if you want hardware connected and permanently monitored.

Thank you for your quick reply.

I am going to use my older version of Cubase (Cubase LE 5), since it works with the UR44.

It just seems strange to me that a newer version of Cubase does not have the same functionality.

But thank you anyway, it was almost driving me crazy……… :slight_smile:

Best regards


Well they mostly moved the functionality inside of Cubase…what exactly are you trying to do that you can’t do in Cubase??

There isnt a need to open up the dspMixFX windows; if you do thats exactly what you’ll get. Whatever fader or effect settings are taken over by Cubase as soon as it latches on the ASIO driver.

The integration with Cubase is exceptional. In the mixer window, 5 hardware channel strips are shown or depending on how you configured the UR44’s inputs. Clicking on the L will enable direct monitoring.

Not sure your question was addressed. Did you close LE5 before opening AI?

Thanks’ for your replies, I got it working now.

Best Regards


Using UR integrated in Cubase 9.5 pro, of course without opening dspMixFx crashes Cubase.
Opening dspMixFx alone showes UR not connected and after few seconds get message “can not use USB port…”

Message “can not use USB port…” is showing when yiu use dspMixFx without Cubase(exited) and if I want to use UR drivers in Cubase (with dspMixFx closed before opening Cubase, of course) it leads to crash Cubase

Are you saying that you cant open CBP 9.5 at all? As in double-click CBP 9.5 icon >splash logo shows > CRASH… > desktop. Is this the sequence of events?

Frankly i have not experience this. However, i believe it may not be possible what you are describing (not doubting rather do not really understand the issue you’ve described). From what i can vaguely remember is that if the UR 44 is not connected, the dspMixFx does not show up… again on my end this step was not tested on my end.

The other solution is if all else fails change a different USB port. Just rem to use a USB 2.0 port.

Also if necessary, trash the CBP preferences and re-do all VST settings.

hope this helps…