Getting this Issue

[viibhuGupta]

        file:///home/vibhu/.local/share/plasma/plasmoids/org.kde.windowbuttons/contents/ui/main.qml:23:1: module "org.kde.appletdecoration" is not installed

[vajdao]

confirmed on my end too!

Trying to install this "Utterly-Sweet-Plasma" theme, and followed all guides, and got the same error message...
What's happening?

Operating System: EndeavourOS
KDE Plasma Version: 6.0.4
KDE Frameworks Version: 6.2.0
Qt Version: 6.7.0
Kernel Version: 6.9.1-arch1-2 (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-6500 CPU @ 3.20GHz
Memory: 15.6 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 1050 Ti/PCIe/SSE2
Manufacturer: MSI
Product Name: MS-7972
System Version: 2.0

[witt-bit]

❯ screenfetch

 ██████████████████  ████████     witt@witt-SwiftHealth-Manjaro
 ██████████████████  ████████     OS: Manjaro 24.0.0 Wynsdey
 ██████████████████  ████████     Kernel: x86_64 Linux 6.6.30-2-MANJARO
 ██████████████████  ████████     Uptime: 2h 29m
 ████████            ████████     Packages: 1519
 ████████  ████████  ████████     Shell: zsh 5.9
 ████████  ████████  ████████     Resolution: 3840x1080
 ████████  ████████  ████████     DE: KDE
 ████████  ████████  ████████     WM: KWin
 ████████  ████████  ████████     GTK Theme: WhiteSur-Dark-solid-nord [GTK2/3]
 ████████  ████████  ████████     Icon Theme: McMojave-circle-dark
 ████████  ████████  ████████     Disk: 361G / 1.2T (33%)
 ████████  ████████  ████████     CPU: Intel Core i7-10700 @ 16x 4.8GHz [65.0°C]
 ████████  ████████  ████████     GPU: Mesa Intel(R) UHD Graphics 630 (CML GT2)
                                  RAM: 11228MiB / 23779MiB

[devyanshnayak]

yes i also try to manually create the folder and move the lib files but then also it didnt work mybe this will work for you

sudo mkdir /usr/lib/qt/qml/org/kde/appletdecoration/
sudo cp -r ~/.local/share/plasma/plasmoids/org.kde.windowbuttons/lib/*  /usr/lib/qt/qml/org/kde/appletdecoration/

i have installed it from kde store and the main.qml file's line 23 says its missing module that's been copied above may be refreshing plasma or reloading all the KDE modules will work!

[devyanshnayak]

i finally found the solution for this
try this

sudo mkdir   /usr/lib64/qt/qml/org/kde/appletdecoration/
sudo cp -r ~/.local/share/plasma/plasmoids/org.kde.windowbuttons/lib/*  /usr/lib64/qt/qml/org/kde/appletdecoration/

or if this dont work try this :

sudo mkdir -p /lib64/qt/qml/org/kde/appletdecoration/
sudo cp -r ~/.local/share/plasma/plasmoids/org.kde.windowbuttons/lib/*  /lib64/qt/qml/org/kde/appletdecoration/

[HasanKulbuzhev]

Я наконец нашел решение этой проблемы. Попробуйте это.

sudo mkdir   /usr/lib64/qt/qml/org/kde/appletdecoration/
sudo cp -r ~/.local/share/plasma/plasmoids/org.kde.windowbuttons/lib/*  /usr/lib64/qt/qml/org/kde/appletdecoration/

или если это не работает, попробуйте это:

sudo mkdir -p /lib64/qt/qml/org/kde/appletdecoration/
sudo cp -r ~/.local/share/plasma/plasmoids/org.kde.windowbuttons/lib/*  /lib64/qt/qml/org/kde/appletdecoration/

Нужно ли ещё что-то делать после этого? У меня не сработало

[witt-bit]

please read it !

This is a prebuilt distribution of Window Buttons Applet for Plasma 6 - WIP which in turn was ported to Plasma 6 by MOODYHUNTER from Window Buttons Applet originally developed by Psifidotos. I am in no way the original developer of this product nor have I modified it in any way. I published this prebuilt distribution so that it can be used a dependency for Plasma Global Themes. 
Click here to get it for Plasma 5 
This can be installed directly from Plasma Widget explorer or by clicking the install button in this page. However, for this to work correctly, the libraries must be installed by running the below command: 

cd && sudo ./.local/share/plasma/plasmoids/org.kde.windowbuttons/lib-install.sh
 
To uninstall the libraries run: 

sudo rm -rf /usr/lib/qt/qml/org/kde/appletdecoration/
 
NOTE: The libraries were built and will be continued to be built in Arch Linux running the latest available version of KDE Plasma. This may or may not work in other linux distribution or older Plasma versions. I do not intend to provide support if it does not work for you. In such a case you should consider building it yourself by following the instructions from here 

Sorry, the above content is still wrong, the following command is normal

Install

sudo mkdir -p /usr/lib/qt6/qml/org/kde/appletdecoration/
sudo cp -r ~/.local/share/plasma/plasmoids/org.kde.windowbuttons/lib/* /usr/lib/qt6/qml/org/kde/appletdecoration/

Uninstall

sudo rm -r /usr/lib/qt6/qml/org/kde/appletdecoration/