Hello,
I have a master licence for MC20 which was very kindly upgraded to included MC21 (I bought it very close to the cut off).
I installed MC21 on the PI and restored my licence - the file I to sent seems identical to the master licence file I already had with MC20 (same name and size). On the pi when I tried to install it via the terminal I got an error message but when I double clicked it on the pi in the file explorer I had both an error message and a confirmation that it was installed successfully.
Apparently it wasn't installed as now MC21 boots up with (25 days remaining) - I'm probably missing something...
Thanks!
Your pi needs an internet connection to install the license and at least version 21.0.7 of MC.
If it didn't work with an internet connection, check the permissions and ownership on the file
Machine Settings.ini in your .jriver/Media\ Center\ 21/Settings directory (and on the directory itself).
If they are OK delete the Machine Settings file and try again.
If it still doesn't work, install the .mjr file from the command line (as the MC user)
aka
mediacenter21 "some file name.mjr"
you need the quotes because of the spaces in the file name.