kscreen up to 1.1.0 (according to kscreen-console) restores the settings of the last session autmatically, no matter if that session was closed in a sane state or not. Under circumstances, especially after experiments with emulators, but also when testing programs, the screens are left in a undesirable state (e.g. wrong resolutions) or the device controllers have a non-linear memory setting because of scrolling or such. This leads to annoying or questionable effects on next startup being difficult to heal, especially for newbies. The recommendable solution would be, make a sane state be saved in the settings and restore this one instead of the last live state. Reproducible: Always
KScreen 5.3 adds more checks that will ensure that KScreen won't try to restore a broken config (not restoring config with no active screens, correctly restoring invalid resolution, etc.). It's not exactly what you suggest ("sane state be saved in the settings and restore this one instead of the last live state"), but should solve some of the problems you described.
Thank you for your reply. I thought of using the "System Settings" config as the master state and not storing any state at the end of each session. I do not know exactly how this happens, but I have stumbled over certain settings that were apparently perfect concerning resolution, active screens, order etc. but they had a severe problem with the frame buffer set up - an effect you can observe when some screensavers set in. Then, the screen is parted vertically or horizontally and partially old content is being displayed. This may happen even after reboot, so I suspected KScreen. Possibly the latter might not exactly have to do with KScreen, as I understand your message?
This is a good suggestion and it is still relevant. The Arch Linux package arandr (a simple visual front end for XRandR) has the feature to save and to restore specific layouts. This would be a helpful addition to current versions kscreen. In recent updates (starting around plasma version 5.13.2) kscreen has become much worse at managing screens properly, particularly in laptops that dock to multiple monitors.
*** Bug 419506 has been marked as a duplicate of this bug. ***
Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with Plasma 5.25 or 5.26? If it is, please change the status to CONFIRMED when replying. If not, or if you can't because you no longer use this setup, you can change the status to RESOLVED WORKSFORME. Thanks a lot!
Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information as soon as possible and set the bug status as REPORTED. Due to regular bug tracker maintenance, if the bug is still in NEEDSINFO status with no change in 30 days the bug will be closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging If you have already provided the requested information, please mark the bug as REPORTED so that the KDE team knows that the bug is ready to be confirmed. Thank you for helping us make KDE software even better for everyone!
This bug has been in NEEDSINFO status with no change for at least 30 days. The bug is now closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging Thank you for helping us make KDE software even better for everyone!