Known issues in the Plasma 5.9 release.
When using Qt 5.6.0 Plasma loads itself incompletely and with long delays. Deadlocks occur in kded5. Use Qt 5.7 instead.
We have received many reports on problems with running Plasma on hardware with graphic cards provided by Intel. We are sorry for the inconvenience and are sorry that we are not able to provide a product which is on par on all systems. Our aim is it to have our software run well on all hardware, but we cannot prevent errors in the underlying stack. Our software was hit by surprise by the issues which are from our view regressions in the underlying driver stack as previous versions worked fine. We would have liked to provide workarounds for these issues which can only be fixed by Intel. Unfortunately we were not able to find a satisfying solution. Given that we present here a list of known workaround which can be tried by affected users.
We encourage our users who experience problems to come to forum.kde.org so that we can help with our knowledge and to help us gather more information to provide better workarounds.
This issue is caused by an Intel driver bug. A reported workaround is to change AccelMethod to UXA in the xorg configuration and restarting the system. Please refer to documentation provided by your distribution on how to change this.
Users told us that enabling DRI3 in xorg configuration can circumvent this problem. An alternative can be to use the new OpenGL ES backend in KWin which also seems to circumvent the problem or disable compositing completely.
To circumvent the issues mentioned above it's also possible to switch the Xorg ddx driver from Intel to modesettings. Many distributions do so by default nowadays.
Environment variables and shutdown scripts are now sourced from ~/.config/plasma-workspace/env and ~/.config/plasma-workspace/shutdown, respectively. Existing scripts from Plasma 4 should be moved there.