Login loop with fresh 19.10 install

So I installed 19.10 fresh from USB. I picked no login required. First reboot after install I'm welcomed inside Ubuntu. But second time I'm prompted to login for no reason. Worst part is that i login with right password and all but it just loops me back to the login screen again. If I enter wrong password, it tells me I'm wrong. Tried to login via terminal and then type "sudo startx". That just led me back to login screen.

Please help me, I'm running a first gen amd ryzen and nvidia 980ti.

Edit: SOLVED! In my answer below.

Solution 1:

I had this issue after upgrading from 19.04 to 19.10.

The solution that worked for me is to switch display manager from GDM3 to LightDM.

If you have installed the lightdm package, just run sudo dpkg-reconfigure gdm3 and select LightDM.

After rebooting you should be able to log in.

I have since found a solution to fix login loop without changing GDM3 to LightDM:

On the login screen, press Ctrl+Alt+F3.
Log in to the shell using your username and password.

Uninstall and reinstall the gdm3 package:

sudo apt-get purge gdm3
sudo apt-get install gdm3

Now just select GDM3, and after a reboot it should work fine.

Solution 2:

SOLVED

That's a problem related to the NVIDIA Kernel Module failing with proprietary drivers. To solve it, do the following steps:

At the login screen, press ctrl+alt+f2 to enter the terminal and login with your name and password
Type sudo nano /etc/default/grub (you can change nano to the text editor of your preference) to edit /etc/default/grub
Change the line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to GRUB_CMDLINE_LINUX_DEFAULT="nomodeset"
Save the edition pressing ctrl+o and exit pressing ctrl+x
Update this grub edit with sudo update-grub
Install lightdm using sudo apt-get install lightdm
Reboot typing sudo reboot