STEPS TO REPRODUCE 1. search for "login screen (sddm)" kcm using the apps launcher and open it 2. click "get new login screens..." button 3. install a theme (I tested with "sugar dark for sddm" theme) 4. when the password dialog to confirm the installation appears, cancel it OBSERVED RESULT an empty error message appears (see the attached screenshot) and the theme is intalled anyway. The theme is present in "Instaaled" section of GHNS window and Discover also lists it as installed. EXPECTED RESULT no error message and the sddm theme is not installed. SOFTWARE/OS VERSIONS Operating System: KDE neon Unstable Edition KDE Plasma Version: 5.16.80 KDE Frameworks Version: 5.59.0 Qt Version: 5.12.0
Created attachment 120163 [details] screenshot
Created attachment 120164 [details] "Installed" section of GHNS window As we can see in the second screenshot, "Installed" section of GHNS window shows the theme as installed but it is not available for selection in the sddm_kcm.
Well it used to crash so I guess we're making progress. :)
*** Bug 422992 has been marked as a duplicate of this bug. ***
This has been fixed some time ago when I was fixing the exact same issue for the dolphin installer :-).
The sddm theme is no longer installed after the password dialog to be canceled, but the empty error message persists. Operating System: KDE neon Unstable Edition KDE Plasma Version: 5.19.80 KDE Frameworks Version: 5.73.0 Qt Version: 5.14.2
Created attachment 130563 [details] canceling plasma settings sync with sddm Possibly related issue: also empty error message when I cancel the authentication to sync plasma settings with sddm. Watch the screen recording please. Operating System: Arch Linux KDE Plasma Version: 5.19.4 KDE Frameworks Version: 5.72.0 Qt Version: 5.15.0
A possibly relevant merge request was started @ https://invent.kde.org/plasma/sddm-kcm/-/merge_requests/2
Git commit 8acacca14eba2c445b0e9dd8a9b4193cb48cfb7d by Alexander Lohnau. Committed on 28/08/2020 at 16:17. Pushed by alex into branch 'master'. Avoid empty message dialogs, cleanup - Choose better QString overloads - Remove unused variables - Add missing emit keywords - Avoid multi-arg method call - Avoid detaching in loop - Do not show empty error messages, for exmple when the user clicks the cancel button FIXED-IN: 5.20 M +3 -2 sddmauthhelper.cpp M +3 -2 sddmthemeinstaller.cpp M +8 -4 src/advancedconfig.cpp M +4 -4 src/sddmkcm.cpp M +1 -5 src/themesdelegate.cpp https://invent.kde.org/plasma/sddm-kcm/commit/8acacca14eba2c445b0e9dd8a9b4193cb48cfb7d