### 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)

}
	}
	{
		HashSet<String> all_functions;
		
		
		static const char *builtin_types_excluded_functions[] = { "dict_to_inst", "inst_to_dict", "bytes_to_var", "bytes_to_var_with_objects", "db_to_linear", "deg_to_rad", "linear_to_db", "rad_to_deg", "randf_range", "ped", "str_to_var", "var_to_str", "var_to_bytes", "var_to_bytes_with_objects", "move_toward", "uri_encode", "uri_decode", "remove_at", "get_rotation_quaternion", "limit_length", "grow_side", "is_absolute_path", "is_valid_int", "lerp", "to_ascii_buffer", "to_utf8_buffer", "to_utf32_buffer", "to_wchar_buffer", "ped", "remap", "rfind", nullptr };
		for (int current_index = 0; builtin_types_excluded_functions[current_index]; current_index++) {
			all_functions.insert(builtin_types_excluded_functions[current_index]);
		}
		
		
		
		
		
		
		
		
		
		List<StringName> classes_list;
		ClassDB::get_class_list(&classes_list);
		for (StringName &name_of_class : classes_list) {
			List<MethodInfo> method_list;
			ClassDB::get_method_list(name_of_class, &method_list, true);
			for (MethodInfo &function_data : method_list) {
				if (!all_functions.has(function_data.name)) {
					all_functions.insert(function_data.name);
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