IEEE1394 port

I am having an issue where I cannot use my MR816X editor due to error message:
Cannot use IEEE1394 port; it is being used by another application
I see others have posted re this issue but I cannot see a resolution through the noise.
Can anyone assist me in layman’s terminology?
MacBookPro, Cubase Pro 8, MR816X

its shows this message usually when cubase is opened (the MR extension is taking control)