I've been downloaded a file from MonoDevelop website but it couldn't execute in my ubuntu, how to open that file?
filename is "monodevelop.flatpakref"
Based on burhanuddin abbas comment there's a problem on Ubuntu 14.04.
Unable to locate package flatpak , because it is not supported for ubuntu 14.04 . Visit here for more details
sudo add-apt-repository ppa:alexlarsson/flatpak.
sudo apt update.
sudo apt install flatpak.
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo.
flatpak install monodevelop.flatpakref.
flatpak run com.xamarin.MonoDevelop (probably, not tested, based on @purlantov answer).
This is very helpfull Install MonoDevelop preview via FlatPak
It worked for me but any time that you want to start MonoDevelop you have to type in console:
flatpak run com.xamarin.MonoDevelop
And there is lot of things that do not work properly. I suggest you to compile it your self. This video help me a lot -> VIDEO
Unfortunately there is no longer pre-compiled package for Ubuntu.