Problem
Hello everyone! I am having a problem with my Ubuntu computer using GDM3. My machine gets to the GDM3 login screen just fine, but whenever I type in my password and hit the button to log in the screen goes blank, and then returns to the GDM3 login screen. I believe it may be rebooting (as terminal text will sometimes show up for half a second), but I am not sure. Please help me solve this issue!
Background
My computer is a Dell XPS 15 with an NVIDIA graphics card which dual boots Ubuntu 18.x (I don't remember the exact version) and Windows 10. Earlier today, I normally use GDM3 but today decided to try out LightDM on my system out of curiosity. I switched to LightDM using the dpkg-reconfigure lightdm command, but I was unable to get LightDM to actually run properly on my system so I used the same command to switch back to GDM3. After switching back to GDM3, I started encountering this error. I've tried every "fix" I've found online, but to no avail.
