Updated yesterday to plasma 5.4 in Kubuntu 15.04 from CI/stable repo. I'm now encountering an irritating bugs: Some windows, not main ones but ones like dialog windows or settings of application aren't properly closed. When I click to close, it disappears for a moment then returns as some kind of unclickable, unselectable sort of background window, in its last state. Dolphin's configure dialog or a 'window specific settings' dialog both trigger this behavior consistently. I'm not sure how to begin diagnosing, just posted here cause I believe it's related to kwin. Any help will be much appreciated.

Sounds like compositing, try SHIFT+Alt+F12 - the window likely disappears and does not show up on second invocation.

In this case "something" (usually some effect) references the texture.
When you close it, the close effect fades out the window and afterwards the referenced texture (the window itself is gone) dangles around.

When you see such window, in konsole run

Code: Select all

qdbus org.kde.KWin /Effects activeEffects

It should print a list of active effects. Anything that's not "blur" or "contrast" is likely the culprit

luebking wrote:Sounds like compositing, try SHIFT+Alt+F12 - the window likely disappears and does not show up on second invocation.

In this case "something" (usually some effect) references the texture.
When you close it, the close effect fades out the window and afterwards the referenced texture (the window itself is gone) dangles around.

When you see such window, in konsole run

Code: Select all

qdbus org.kde.KWin /Effects activeEffects

It should print a list of active effects. Anything that's not "blur" or "contrast" is likely the culprit

Thanks. It was the transparency effect. Used to make those [dialog] windows always translucent for fancy. Guess I'll have to put a stop to that.

Sounds like https://bugs.kde.org/show_bug.cgi?id=338748
Can you somewhat reliably reproduce it?
What's the ouput of "kwin_x11 --version"?

(The strategy si to fix bugs, not to avoid buggy features

luebking wrote:Sounds like https://bugs.kde.org/show_bug.cgi?id=338748
Can you somewhat reliably reproduce it?
What's the ouput of "kwin_x11 --version"?

(The strategy si to fix bugs, not to avoid buggy features

Ok, went searching for bugs but I couldn't phrase it well. Thanks for finding that. I might have to open a new bug though, since that has to do with Nvidia graphics.
Anyways I'm not at my linux system now, will contribute once I get to it.

The linked bug isn't specifically linked to the nvidia driver (actually, since the reporter never returned, we don't know what it's related to - but it sounds like your issue)