The most common reason for this error message is when you try to load the 32-bit version of Brazil into 64-bit Rhino 5.
The first releases of Brazil printed on CD's didn't have the 64-bit version, so if you try to install Brazil with one of these CD's on to your 64-bit Rhino 5, you will run into this problem.
Please go to the Brazil download page and download the installer for the latest 64-bit version of Brazil. Install Brazil with the latest installer and this issue should be resolved.
Didn't this solution solve your problem?
Please contact McNeel Support.