I copy/paste the log of the running of the AppImage
(process:5740): Gtk-WARNING **: 20:13:34.390: Locale not supported by C library.
Using the fallback ‘C’ locale.
Gtk-Message: 20:13:34.408: Failed to load module “xapp-gtk3-module”
/usr/lib/x86_64-linux-gnu/gvfs/libgvfscommon.so: undefined symbol: g_task_set_name
Failed to load module: /usr/lib/x86_64-linux-gnu/gio/modules/libgvfsdbus.so
/usr/lib/x86_64-linux-gnu/gvfs/libgvfscommon.so: undefined symbol: g_task_set_name
Failed to load module: /usr/lib/x86_64-linux-gnu/gio/modules/libgioremote-volume-monitor.so
/usr/lib/x86_64-linux-gnu/gvfs/libgvfscommon.so: undefined symbol: g_task_set_name
Failed to load module: /usr/lib/x86_64-linux-gnu/gio/modules/libgvfsdbus.so
/usr/lib/x86_64-linux-gnu/gvfs/libgvfscommon.so: undefined symbol: g_task_set_name
Failed to load module: /usr/lib/x86_64-linux-gnu/gio/modules/libgioremote-volume-monitor.so
I agree. All of the required files should be packaged along with the AppImage, so the ‘error’ messages are likely redundant — it’s a bit too long-winded to explain here, but you should find that everything works as expected.