Installation Broken

[CharlesAverill]

Describe the Bug

Installation fails with this error:
The settings of extension desktop-cube@schneegans.github.com had an error:

Gtk.BuilderError: .:51:33 Invalid property: GtkMenuButton.icon-name

Stack trace:

PreferencesDialog@/home/charlesaverill/.local/share/gnome-shell/extensions/desktop-cube@schneegans.github.com/prefs.js:43:19
buildPrefsWidget@/home/charlesaverill/.local/share/gnome-shell/extensions/desktop-cube@schneegans.github.com/prefs.js:237:16
_init@resource:///org/gnome/Shell/Extensions/js/extensionsService.js:207:40
OpenExtensionPrefsAsync/<@resource:///org/gnome/Shell/Extensions/js/extensionsService.js:122:28
asyncCallback@resource:///org/gnome/gjs/modules/core/overrides/Gio.js:115:22
run@resource:///org/gnome/Shell/Extensions/js/dbusService.js:177:20
main@resource:///org/gnome/Shell/Extensions/js/main.js:19:13
run@resource:///org/gnome/gjs/modules/script/package.js:206:19
start@resource:///org/gnome/gjs/modules/script/package.js:190:8
@/usr/share/gnome-shell/org.gnome.Shell.Extensions:1:17

Steps to reproduce the behavior:
Install using either the GitHub releases or https://extensions.gnome.org/

Expected Behavior

Standard installation followed by use

System

• Pop!_OS 21.04
• Desktop Cube 8
• GNOME Shell 3.38.4

[maurestor]

Same error
The settings of extension desktop-cube@schneegans.github.com had an error:

Gtk.BuilderError: .:51:33 Invalid property: GtkMenuButton.icon-name

Stack trace:

PreferencesDialog@/home/restor/.local/share/gnome-shell/extensions/desktop-cube@schneegans.github.com/prefs.js:43:19
buildPrefsWidget@/home/restor/.local/share/gnome-shell/extensions/desktop-cube@schneegans.github.com/prefs.js:237:16
_init@resource:///org/gnome/Shell/Extensions/js/extensionsService.js:207:40
OpenExtensionPrefsAsync/<@resource:///org/gnome/Shell/Extensions/js/extensionsService.js:122:28
asyncCallback@resource:///org/gnome/gjs/modules/core/overrides/Gio.js:115:22
run@resource:///org/gnome/Shell/Extensions/js/dbusService.js:177:20
main@resource:///org/gnome/Shell/Extensions/js/main.js:19:13
run@resource:///org/gnome/gjs/modules/script/package.js:206:19
start@resource:///org/gnome/gjs/modules/script/package.js:190:8
@/usr/share/gnome-shell/org.gnome.Shell.Extensions:1:17

Ubuntu 21.04
GNOME 3.38.4

[Schneegans]

Hi there! I am sorry, but the extension requires at least GNOME Shell 40. Here are some more details: #16.