Mousepad crashes when detaching tab

Version: 0.4.2 OS: Xubuntu 20.10

Mousepad crashes when detaching tab to a new window. Issue could be related with the underlying window manager (i3 tiling window manager). There is a possibility that bug persists in later versions as well.

Console output after crash:

(mousepad:16181): GLib-GObject-CRITICAL **: 16:27:52.134: g_object_ref: assertion 'G_IS_OBJECT (object)' failed

(mousepad:16181): Gtk-CRITICAL **: 16:27:52.134: gtk_container_get_focus_child: assertion 'GTK_IS_CONTAINER (container)' failed

(mousepad:16181): GLib-GObject-CRITICAL **: 16:27:52.134: g_object_unref: assertion 'G_IS_OBJECT (object)' failed

(mousepad:16181): Gtk-CRITICAL **: 16:27:52.135: gtk_container_get_focus_child: assertion 'GTK_IS_CONTAINER (container)' failed
**
Gtk:ERROR:../../../../gtk/gtkwidget.c:5871:gtk_widget_get_frame_clock: assertion failed: (window != NULL)
Bail out! Gtk:ERROR:../../../../gtk/gtkwidget.c:5871:gtk_widget_get_frame_clock: assertion failed: (window != NULL)