Cubase 14 user here, same problem, it doesn’t open REX files, why??
I checked on C:\Program Files\Steinberg\Cubase 14\Components and there is the Rex library dll file, I also checked on C:\Program Files\Common Files\Steinberg\ and there was not a “Shared Components” folder as one user suggested, so I created that folder and copied the dll file in there, but it still can’t open rex files…
How are you opening the REX files?
Did you have a previous version of Cubase where this worked, i.e. can you open and play and existing project that uses REX files?