So I run Kubuntu(kde plasma) and I was importing a source in Intellij, but after I chose the file, kwin just crashed and the error is seg fault, and that somehow damaged the setup because now I can not run Kwin, it would always crash when I launched it, I have tried a bit of Googling to no avail. Any help would be highly appreciated

Error:
https://imgur.com/a/T1ISXyH

Normaly dont't start kwin directly, it is just the composer. The windowsmanger, normaly by default SDDM, you can start/stop with the with main kernel administration tool

>sysctl start sddm
or
>sysctl stop sddm

When you would like to look for more information

>info sddm
>info sysctl

grumpfel wrote:Normaly dont't start kwin directly, it is just the composer. The windowsmanger, normaly by default SDDM, you can start/stop with the with main kernel administration tool

>sysctl start sddm
or
>sysctl stop sddm

When you would like to look for more information

>info sddm
>info sysctl

Hello! Thanks for your help, unfortunately, the solution did not work, sysctl seems to control their variable instead of start and stop of them
I tried systemctl instead and started my display manager, which is lightdm, it didn't do anything.

If you run Kubuntu the default should be SDDM, not lightdm. Defaults have a reason...

Mamarok wrote:If you run Kubuntu the default should be SDDM, not lightdm. Defaults have a reason...

I'm not sure how it is suppose to be, but it is indeed lightdm that I has as display manager, should I change it and if I should, how.

Mamarok wrote:If you run Kubuntu the default should be SDDM, not lightdm. Defaults have a reason...

So should I switch over to SDDM? Would it affect anything?

You should first check you have a fully updated Kubuntu version, and install SDDM, as this si the default and recommended WIndowmanager.

You didn't tell which exact Plasma version you are running, this is usually a good idea when asking for help (See System Settings -> System Adminstration -> System Information.) This information can be copied to the clipboard and inserted in the post, it should look like this (my setup):

Operating System: Kubuntu 21.04
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 5.86.0
Qt Version: 5.15.2
Kernel Version: 5.11.0-35-generic (64-bit)
Graphics Platform: X11
Processors: 12 × AMD Ryzen 5 4600H with Radeon Graphics
Memory: 62,2 GiB of RAM
Graphics Processor: AMD RENOIR

Mamarok wrote:You should first check you have a fully updated Kubuntu version, and install SDDM, as this si the default and recommended WIndowmanager.

You didn't tell which exact Plasma version you are running, this is usually a good idea when asking for help (See System Settings -> System Adminstration -> System Information.) This information can be copied to the clipboard and inserted in the post, it should look like this (my setup):

Operating System: Kubuntu 21.04
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 5.86.0
Qt Version: 5.15.2
Kernel Version: 5.11.0-35-generic (64-bit)
Graphics Platform: X11
Processors: 12 × AMD Ryzen 5 4600H with Radeon Graphics
Memory: 62,2 GiB of RAM
Graphics Processor: AMD RENOIR

Hey!
So I have tried switch to SDDM with dpkg-reconfigure lightdm, it worked but didn't help.
And I am using the newest kubuntu and installed the new kde plasma beta from the anniversary.
Operating system: Kubuntu 21.04
KDE Plasma Version: 5.22.90
KDE framework version: 5.86.0
Qt version: 5.15.2
Kernel version: 5.11.0-34-generic (64 bit)
Graphics platform: X11
Processor: AMD Ryzen 9 5950X (32) @ 3.400GHz
Memory: 32Gb
Graphics processor: rtx 3090
Is that fine?

Edit: I couldn't access system information because kwin is straight up not running, I got these info from kf5-config, neofetch, and my own knowledge of the hardware.