### Godot version

4.0 RC1

### System information

Linux Mint 20.3 Cinnamon

### Issue description

Tried converting a 3.5 game to 4.0 RC1. The conversion popup menu closed after a few seconds, and trying to edit the game crashes the entire engine with the following errors, which seem to be related to one music file not loading:
![errors](https://user-images.githubusercontent.com/125468288/219127087-f5a78035-4e4a-4625-aadb-e0cde6d5ac3d.png)

Not sure what's causing the issue, because when I created a new project with only that file and converted it I didn't get these errors, but consistently get them when trying to convert that game.

### Steps to reproduce

- Download the reproduction project below
- Import in Godot 4.0, and click "convert full project"
- If the bug happens, the engine will crash whenever trying to edit or run the converted project

### Minimal reproduction project

[Music Convertor Crash Demo.zip](https://github.com/godotengine/godot/files/10746591/Music.Convertor.Crash.Demo.zip)

RegEx input_map_keycode = RegEx("\\b,\"((physical_)?)scancode\":(\\d+)\\b");
	
	RegEx joypad_button_index = RegEx("\\b,\"button_index\":(\\d+),(\"pressure\":\\d+\\.\\d+,\"pressed\":(false|true))\\b");
	RegEx joypad_axis = RegEx("\\b,\"axis\":(\\d+)\\b");
	
	
	int joypad_button_mappings[23] = { 0, 1, 2, 3, 9, 10, -1 , -1 , 7, 8, 4, 6, 11, 12, 13, 14, 5, 15, 16, 17, 18, 19, 20 };
	
	LocalVector<RegEx *> class_regexes;
	RegEx class_temp_tscn = RegEx("\\bTEMP_RENAMED_CLASS.tscn\\b");
	RegEx class_temp_gd = RegEx("\\bTEMP_RENAMED_CLASS.gd\\b");
	RegEx class_temp_shader = RegEx("\\bTEMP_RENAMED_CLASS.shader\\b");
	LocalVector<String> class_temp_tscn_renames;
	LocalVector<String> class_temp_gd_renames;
	LocalVector<String> class_temp_shader_renames;
	
	LocalVector<RegEx *> enum_regexes;
	LocalVector<RegEx *> gdscript_function_regexes;
	LocalVector<RegEx *> project_settings_regexes;
	LocalVector<RegEx *> project_godot_regexes;
	LocalVector<RegEx *> input_map_regexes;
	LocalVector<RegEx *> gdscript_properties_regexes;
	LocalVector<RegEx *> gdscript_signals_regexes;
	LocalVector<RegEx *> shaders_regexes;
	LocalVector<RegEx *> builtin_types_regexes;
	LocalVector<RegEx *> theme_override_regexes;
	LocalVector<RegEx *> csharp_function_regexes;
	LocalVector<RegEx *> csharp_properties_regexes;
	LocalVector<RegEx *> csharp_signal_regexes;
	RegExContainer() {