I'm currently running Ubuntu GNOME 17.04 on my laptop, and things have been pretty smooth. Today, I felt kinda bored, and so I thought I'd try out the Deepin Desktop Environment. I followed the instructions from another question on this website. The instructions were to type the following commands in Terminal:
sudo add-apt-repository ppa:leaeasy/dde
sudo apt-get update
sudo apt-get install dde
Once that finished, I rebooted and saw the login screen for Deepin. I logged in, and went around all the features. But after a while, I got bored and wanted to switch back to GNOME. I logged out, and logged into GNOME. I opened Terminal, and typed the following command: (NOTE: All the deepin apps were available in my GNOME session, and would work. Although, I'd get an error report after I'd close them. And the Deepin Terminal was set as my default terminal.).
sudo apt purge dde ; sudo apt autoremove
I thought the job was done. But after I rebooted, I still got the Deepin login screen (My default was LightDM with the Unity Greeter). I selected GNOME from the list of DEs. But after logging into GNOME, I saw that the Deepin Terminal was still there (And set as the default terminal). I tried running my previous commands again, but it said that the package dde wasn't found. Now if I try logging into Deepin, it logs in, but the screen is void of anything except for the wallpaper. What do I do? I haven't found a solution for this anywhere online.