[MonoDevelop] Can't retrieve Flatpak for Monodevelop

[n4ida at cox.net]

When I try to install the Flatpak package for Monodevelop I get the following response. Can someone please help.

pi at raspberrypi:~/Downloads $ sudo flatpak install --user --from https://download.mono-project.com/repo/monodevelop.flatpakref
Installing: com.xamarin.MonoDevelop/arm/stable
Installing: com.xamarin.MonoDevelop/arm/stable from com.xamarin.MonoDevelop-1-origin
error: No such branch 'app/com.xamarin.MonoDevelop/arm/stable' in repository summary
pi at raspberrypi:~/Downloads $ 

Thanks Al