### Godot version

3.5.1mono

### System information

windows10

### Issue description

Error message
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).
See "Steps to reproduce for details"

### Steps to reproduce

Set an external text editor
Create a script
Drop the script to the built-in text editor like this image:
![image](https://user-images.githubusercontent.com/119792950/209504041-039f2620-5e42-4c0f-8c41-cd24486fb3d2.png)
And got error message:
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).

### Minimal reproduction project

An empty project
ADD_SIGNAL(MethodInfo("goto_line", PropertyInfo(Variant::INT, "line")));
}
ScriptEditorQuickOpen::ScriptEditorQuickOpen() {
	VBoxContainer *vbc = memnew(VBoxContainer);
	add_child(vbc);
	search_box = memnew(LineEdit);
	vbc->add_margin_child(TTR("Search:"), search_box);
	search_box->connect("text_changed", callable_mp(this, &ScriptEditorQuickOpen::_text_changed));
	search_box->connect("gui_input", callable_mp(this, &ScriptEditorQuickOpen::_sbox_input));
	search_options = memnew(Tree);
	vbc->add_margin_child(TTR("Matches:"), search_options, true);
	set_ok_button_text(TTR("Open"));
	get_ok_button()->set_disabled(true);
	register_text_enter(search_box);
	set_hide_on_ok(false);
	search_options->connect("item_activated", callable_mp(this, &ScriptEditorQuickOpen::_confirmed));
	search_options->set_hide_root(true);
	search_options->set_hide_folding(true);
	search_options->add_theme_constant_override("draw_guides", 1);
}
ScriptEditor *ScriptEditor::script_editor = nullptr;
String ScriptEditor::_get_debug_tooltip(const String &p_text, Node *_se) {