Loading Screen coming and going after upgrading to Plasma 5.5.3

[trintadosete]

I decided to try Plasma 5.5.3, I added the ppa and upgraded. Everything looked fine until I reboot.
Then, the loading screen keeps coming and going. Alternating (for a few seconds) between the loading screen (with no progress in the progress bar) and a blank screen.

I checked online and it seems that there are some issues with Plasma 5.5.3 and it seems that some solutions may work for me. However, I cant get a command line. When I press Ctrl+Alt+F1, I go to tty, but then the "loading screen" appears over it again and take me out of the command line. I would have to press Ctrl+Alt+F1 again (and lose the screen a few seconds later).
Being honest, I have repeated this procedure a couple of times until I manage to log in. However, it is impossible to write a proper command this way...

Does anyone have an idea of how I can get a "proper" command line?

[trintadosete]

Is it possible to force CLI mode from the boot? I mean, is there an parameter for Grub that would give a CLI mode instead of an visual interface?

[sithlord48]

login and stop the display manager

sudo systemctl stop sddm

if sddm does't work try lightdm (not sure the default DM for that kubuntu release)

[trintadosete]

I solved the problem by booting via USB and editing the sddm.conf file to avoid auto-login. Then, I could use ctrl+alt+f1.