After upgrading to the new Ubuntu version the minecraft launcher would not run at all. Uninstalling it and downloading it will not help at all. When clicking it I will hear the hard-drive working for about a second, and nothing will happen. I cannot play minecraft if the launcher does not work. It is installed as Minecraft.deb
We need to see your full launcher log, you should be able to find it in your .minecraft folder. Please upload it to your ticket.