I'm currently still having this issue when I enable the extension for the first time. At reenabling, it is gone. It seems like it is the line 31 in the extension.js file: "box.add(output, {y_fill: false, y_align: St.Align.MIDDLE});" What would be a better approach? And should I remove my log-statements in the released extension? Some code tried to set a deprecated GObject property. 0 _patchContainerClass/containerClass.prototype.child_set() ["resource:///org/gnome/shell/ui/environment.js":34:12] 1 _patchContainerClass/containerClass.prototype.add() ["resource:///org/gnome/shell/ui/environment.js":43:17] 2 enable() ["/home/y500vbmanjaro/.local/share/gnome-shell/extensions/executor@raujonas.github.io/extension.js":31:8] 3 _callExtensionEnable() ["resource:///org/gnome/shell/ui/extensionSystem.js":165:31] 4 _onEnabledExtensionsChanged/<() ["resource:///org/gnome/shell/ui/extensionSystem.js":470:17] 5 forEach() ["self-hosted":266:12] 6 _onEnabledExtensionsChanged() ["resource:///org/gnome/shell/ui/extensionSystem.js":469:10] 7 _onEnabledExtensionsChanged() ["self-hosted":1005:16] 8 _init/createCheckedMethod/<() ["resource:///org/gnome/gjs/modules/core/overrides/Gio.js":529:45] 9 enableExtension() ["resource:///org/gnome/shell/ui/extensionSystem.js":192:28] 10 EnableExtension() ["resource:///org/gnome/shell/ui/shellDBus.js":307:37] 11 _handleMethodCall() ["resource:///org/gnome/gjs/modules/core/overrides/Gio.js":327:37] 12 _wrapJSObject/<() ["resource:///org/gnome/gjs/modules/core/overrides/Gio.js":404:33]

It's probably the `y_fill` property, since I don't see that property in the documentation. In any case, you should be using `Clutter.Actor.add_child()` and setting the properties of the child in the constructor: * https://gjs-docs.gnome.org/clutter5~5_api/clutter.actor * https://gjs-docs.gnome.org/clutter5~5_api/clutter.actor#method-add_child ``` let output = new StLabel({ y_expand: true, // aligning center doesn't make sense if this is false y_align: Clutter.ActorAign.CENTER, // You should prefer Clutter constants for clutter properties }); ```