Schwerwiegender Fehler in dem Programm Meld (Python)

Schon interessant was für schwerwiegende Fehler so Alltagswerkzeuge wie Meld haben:

2021-09-16 03:50:07,564 CRITICAL Gtk: gtk_widget_get_scale_factor: assertion 'GTK_IS_WIDGET (widget)' failed
2021-09-16 03:50:07,564 CRITICAL Gtk: gtk_widget_get_scale_factor: assertion 'GTK_IS_WIDGET (widget)' failed
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/meld/dirdiff.py", line 1050, in on_treemodel_row_deleted
self.current_path = refocus_deleted_path(model, path)
File "/usr/lib/python3/dist-packages/meld/treehelpers.py", line 59, in refocus_deleted_path
new_path = tree_path_prev(path)
File "/usr/lib/python3/dist-packages/meld/treehelpers.py", line 32, in tree_path_prev
return path[:-1] + (path[-1] - 1,)
TypeError: can only concatenate list (not "tuple") to list
2021-09-16 03:57:14,464 CRITICAL Gtk: gtk_widget_get_scale_factor: assertion 'GTK_IS_WIDGET (widget)' failed
2021-09-16 03:57:14,464 CRITICAL Gtk: gtk_widget_get_scale_factor: assertion 'GTK_IS_WIDGET (widget)' failed

Das Schlimme ist; der Benutzer bekommt noch nicht einmal etwas davon mit, weil der Fehler nur in der Konsole angezeigt wird.