Nextcloud Client not accepting OS Theme in Linux Mint 19

📱 Desktop & mobile clients 💻 Desktop
1

Hi,

i switched from Linux Mint 18.3 to 19, and noticed an odd behaviour:
I like the dark theme a lot since it is easier on the eyes. On LM 18.3 the client used whatever theme was selected by the OS (see screenshot)

3
31237×690 53 KB

Under 19, the client does not use any theme, not even the standard theme from LM (see screenshot)
19
191275×796 69.9 KB

I thought about posting this on Issues · nextcloud/client_theming · GitHub but it is readonly now, so i thought i should post here.
Can someone explain why this happens? It is a clean install in both cases …

greetings

STonE

2

I also discovered this problem in a few other programs, so i decided to post this on the Linux Mint forums instead: https://forums.linuxmint.com/viewtopic.php?f=47&t=273055&p=1494396#p1494396

It seems to be a qt-problem, and can be fixed (at least for nextcloud-client) by the following:

    sudo apt install qt5ct qt4-qtconfig
    qt5ct -> Style: GTK2 -> Apply, OK
    qtconfig-qt4 -> GUI Style -> GTK+ -> File -> Save, Exit
    sudo reboot