I just received a brand new Fireface UFX+ and was looking forward to using it. When I downloaded the latest driver that RME claims is compatible with Big Sur, I got the following message: "Fireface USB Driver can't be installed on this disk. This driver package can not be installed on Big Sur."

Do I need to return the unit to the dealer, or is there a solution?

I quadruple-checked to make sure that I was downloading the absolutely latest driver and that I was following the installation instructions carefully.