Arch Linux

nirjharnd

Member

Registered: 2025-03-08

Posts: 3

[SOLVED] QT apps are not launching from Cinnamon Menu

Hi,

Background: I am in the process of migrating from Mint to Arch. Last night I have manually installed Arch Linux. I am using Cinnamon with X11.

Issue: Qt apps like Strawberry, Qbittorrent, QT6CT  etc. are not launching from default Cinnamon menu. They are launching absolutely fine from terminal, even when I am appending %U as stated in the .desktop files. GTK apps do not have such issue, only QT apps.

Any help will be appreciable. Thanks.

Additional Info: I tried launching the associated .desktop files in terminal using gtk-launch command and the logs are as follows:

$ gtk-launch org.strawberrymusicplayer.strawberry.desktop
$ 19:39:07.280 INFO  main:176                         Strawberry 1.2.7 Qt "6.8.2"
19:39:07.280 INFO  main:177                         "Arch Linux unknown - (linux 6.12.17-1-lts) [x86_64]"
19:39:07.448 ERROR logging:88(GLib-GObject)         cannot register existing type 'GdkDisplayManager'
19:39:07.448 ERROR logging:88(GLib)                 g_once_init_leave_pointer: assertion 'result != 0' failed
19:39:07.448 ERROR logging:88(GLib-GObject)         g_object_new_with_properties: assertion 'G_TYPE_IS_OBJECT (object_type)' failed
19:39:07.448 ERROR logging:88(GLib-GObject)         invalid (NULL) pointer instance
19:39:07.448 ERROR logging:88(GLib-GObject)         g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
19:39:07.448 ERROR logging:88(GLib-GObject)         invalid (NULL) pointer instance
19:39:07.448 ERROR logging:88(GLib-GObject)         g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
19:39:07.452 ERROR logging:88(GLib-GObject)         cannot register existing type 'GdkDisplay'
19:39:07.452 ERROR logging:88(GLib)                 g_once_init_leave_pointer: assertion 'result != 0' failed
19:39:07.452 ERROR logging:88(GLib-GObject)         g_type_register_static: assertion 'parent_type > 0' failed
19:39:07.452 ERROR logging:88(GLib)                 g_once_init_leave_pointer: assertion 'result != 0' failed
19:39:07.452 ERROR logging:88(GLib-GObject)         g_object_new_with_properties: assertion 'G_TYPE_IS_OBJECT (object_type)' failed
$ 

Last edited by nirjharnd (2025-03-08 14:31:39)

nirjharnd

Member

Registered: 2025-03-08

Posts: 3

Re: [SOLVED] QT apps are not launching from Cinnamon Menu

It seems I have managed to solve it.

Solution: It seems the culprit was qt6gtk. I have removed that package and reverted to QT_QPA_PLATFORMTHEME=gtk3. It solved the issue. I have removed qt6ct package as well because I do not need it if I can't use qt6gtk2.

DeadBaron

Member

Registered: 2025-12-26

Posts: 1

Re: [SOLVED] QT apps are not launching from Cinnamon Menu

It seems I have managed to solve it.

Solution: It seems the culprit was qt6gtk. I have removed that package and reverted to QT_QPA_PLATFORMTHEME=gtk3. It solved the issue. I have removed qt6ct package as well because I do not need it if I can't use qt6gtk2.

Dude, thank you for this, was fighting half the day after a system update and noticed all qt based apps like kcalc stopped working. Literally nothing helped until removing qt6gtk and qt6ct and setting the theme to gtk3

At the risk of getting banned or warned for necroposting, wanted to let you know you've helped at least me and God knows who else that stumbled across this from a search engine.  Would have been a DM but couldn't find how to do it.  Been years since I used a forum.