Hi,

since update to ubuntu 19.10 and new KDE 5.17.5 i have a weird behavior.

I use to have a personal background image on my login screen/locking screen. But even this image is available in Setting -> startup & shutdown (as you can see on the image attached), it is not anymore displayed as before.



while my background image that should be displayed is:


What's happened ?

thx

Did you change something before this happened? My personalised image displays quite fine, running the same Distro and Plasma version as you do.

No i changed nothing. I just upgrade distro version that's all.

Is it not necessary to synchronize after background image was changed ?

I've never heard about such sync after changing settings as till now it was not necessary

I'm also not sure, if such a sync is necessary In the text above is nothing about background image ... But, did it help ?

raphaelra wrote:I'm also not sure, if such a sync is necessary In the text above is nothing about background image ... But, did it help ?

I gave a try to it and nothing changed. As i told previously, i've never heard before, that a sync is necessary to change login screen background image as it usually just asks root password to set it up.

Could it be that you changed location for this image file? It has to be in a global folder, not just in your /home folder

Mamarok wrote:Could it be that you changed location for this image file? It has to be in a global folder, not just in your /home folder

It has been always in /home/alain/pictures folder since the beginning. So why should it be problem now ?

The weird thing is that system requires "root" permission (so sudo) to record that i set a new background image for login screen / lock screen...i do not remember such need from system before upgrade.

You always had to have root rights to change SDDM settings, as those are not in the Plasma user space, but located in /etc/sddm.conf.d

I have almost the same issue.
Clean install of Kubuntu 20.04
I tried to change the login background image to a specific image, it seemed to accept it, but now I have a black background and nothing I do fixes it.
I tried resetting it back to the default breeze login screen, but it made no difference.
I also tired the 'Get new login screens', picked a nice one, installed and set it - nothing, still just a black background on the login screen.
Any ideas ?
( this used to work when I had Kubuntu 18.04 installed ).

UPDATE: I completely uninstalled the login screens and installed a new one from the 'Get new login screens' - this is now working.

For anyone stumbling across this thread trying to figure out why the lock screen isn't changing, the login screen and the lock screen are separate things and their backgrounds are configured separately. I think the original poster was confused about this (as was I) since they mention "login screen/locking screen".
Probably most people want/expect them to have the same background, hence the confusion.
I am on Plasma 5.19.5 and changed the lock screen background through Settings > "Workspace Behavior" > "Screen Locking" > "Appearance" tab.

Further to everyone's answers, I found out that you can change the login (startup) wallpaper by clicking the image icon on the theme preview:

https://imgur.com/a/NvZR92U