#42 Segfault when trying to edit/remove extra button

[The Compiler]

When I try to remove/edit an extra button in the settings:

(easystroke:5573): Gtk-CRITICAL **: gtk_tree_model_get_iter: assertion 'path->depth > 0' failed

(easystroke:5573): Gtk-CRITICAL **: gtk_list_store_get_value: assertion 'iter_is_valid (iter, list_store)' failed

Thread 1 "easystroke" received signal SIGSEGV, Segmentation fault.
0x0000000000473baa in ?? ()
(gdb) bt
#0  0x0000000000473baa in  ()
#1  0x000000000046b669 in  ()
#2  0x00007ffff5c069b8 in Glib::SignalProxyNormal::slot0_void_callback(_GObject*, void*) () at /usr/lib/libglibmm-2.4.so.1
#3  0x00007ffff334bf75 in g_closure_invoke () at /usr/lib/libgobject-2.0.so.0
#4  0x00007ffff335e053 in  () at /usr/lib/libgobject-2.0.so.0
#5  0x00007ffff3366bcc in g_signal_emit_valist () at /usr/lib/libgobject-2.0.so.0
#6  0x00007ffff3366faf in g_signal_emit () at /usr/lib/libgobject-2.0.so.0
#7  0x00007ffff53c4c6d in  () at /usr/lib/libgtk-3.so.0
#8  0x00007ffff53c4cd5 in  () at /usr/lib/libgtk-3.so.0
#9  0x00007ffff6bc5450 in Gtk::Button_Class::released_callback(_GtkButton*) () at /usr/lib/libgtkmm-3.0.so.1
#10 0x00007ffff334bf75 in g_closure_invoke () at /usr/lib/libgobject-2.0.so.0
#11 0x00007ffff335d95c in  () at /usr/lib/libgobject-2.0.so.0
#12 0x00007ffff3366bcc in g_signal_emit_valist () at /usr/lib/libgobject-2.0.so.0
#13 0x00007ffff3366faf in g_signal_emit () at /usr/lib/libgobject-2.0.so.0
#14 0x00007ffff53c30d0 in  () at /usr/lib/libgtk-3.so.0
#15 0x00007fffee0ae1c8 in ffi_call_unix64 () at /usr/lib/libffi.so.6
#16 0x00007fffee0adc2a in ffi_call () at /usr/lib/libffi.so.6
#17 0x00007ffff334cc8a in g_cclosure_marshal_generic_va () at /usr/lib/libgobject-2.0.so.0
#18 0x00007ffff334c1a4 in  () at /usr/lib/libgobject-2.0.so.0
#19 0x00007ffff33668bd in g_signal_emit_valist () at /usr/lib/libgobject-2.0.so.0
#20 0x00007ffff3366faf in g_signal_emit () at /usr/lib/libgobject-2.0.so.0
#21 0x00007ffff547ea01 in  () at /usr/lib/libgtk-3.so.0
#22 0x00007ffff334ed27 in g_cclosure_marshal_VOID__BOXEDv () at /usr/lib/libgobject-2.0.so.0
#23 0x00007ffff334c1a4 in  () at /usr/lib/libgobject-2.0.so.0
#24 0x00007ffff33668bd in g_signal_emit_valist () at /usr/lib/libgobject-2.0.so.0
#25 0x00007ffff3366faf in g_signal_emit () at /usr/lib/libgobject-2.0.so.0
#26 0x00007ffff547bcce in  () at /usr/lib/libgtk-3.so.0
#27 0x00007ffff547d2fb in  () at /usr/lib/libgtk-3.so.0
#28 0x00007ffff547ff7d in  () at /usr/lib/libgtk-3.so.0
#29 0x00007ffff544d40e in gtk_event_controller_handle_event () at /usr/lib/libgtk-3.so.0
#30 0x00007ffff561205b in  () at /usr/lib/libgtk-3.so.0
#31 0x00007ffff6c79944 in Gtk::Widget::on_button_release_event(_GdkEventButton*) () at /usr/lib/libgtkmm-3.0.so.1
#32 0x00007ffff6c7bb44 in Gtk::Widget_Class::button_release_event_callback(_GtkWidget*, _GdkEventButton*) () at /usr/lib/libgtkmm-3.0.so.1
#33 0x00007ffff54c7a31 in  () at /usr/lib/libgtk-3.so.0
#34 0x00007ffff334c1a4 in  () at /usr/lib/libgobject-2.0.so.0
#35 0x00007ffff3366391 in g_signal_emit_valist () at /usr/lib/libgobject-2.0.so.0
#36 0x00007ffff3366faf in g_signal_emit () at /usr/lib/libgobject-2.0.so.0
#37 0x00007ffff56142fc in  () at /usr/lib/libgtk-3.so.0
#38 0x00007ffff54c4a3e in  () at /usr/lib/libgtk-3.so.0
#39 0x00007ffff54c6a7e in gtk_main_do_event () at /usr/lib/libgtk-3.so.0
#40 0x00007ffff4fd8be5 in  () at /usr/lib/libgdk-3.so.0
#41 0x00007ffff5009bd2 in  () at /usr/lib/libgdk-3.so.0
#42 0x00007ffff3073587 in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#43 0x00007ffff30737f0 in  () at /usr/lib/libglib-2.0.so.0
#44 0x00007ffff307389c in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#45 0x00007ffff442554d in g_application_run () at /usr/lib/libgio-2.0.so.0
#46 0x000000000041c46f in  ()
#47 0x00007ffff2408291 in __libc_start_main () at /usr/lib/libc.so.6
#48 0x000000000041ceca in  ()