### 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)

public:
	
	RegEx reg_is_empty = RegEx("\\bempty\\(");
	RegEx reg_super = RegEx("([\t ])\\.([a-zA-Z_])");
	RegEx reg_json_to = RegEx("\\bto_json\\b");
	RegEx reg_json_parse = RegEx("([\t ]{0,})([^\n]+)parse_json\\(([^\n]+)");
	RegEx reg_json_non_new = RegEx("([\t ]{0,})([^\n]+)JSON\\.parse\\(([^\n]+)");
	RegEx reg_json_print = RegEx("\\bJSON\\b\\.print\\(");
	RegEx reg_export_simple = RegEx("export\\(([a-zA-Z0-9_]+)\\)[ ]+var[ ]+([a-zA-Z0-9_]+)");
	RegEx reg_export_typed = RegEx("export\\(([a-zA-Z0-9_]+)\\)[ ]+var[ ]+([a-zA-Z0-9_]+)[ ]*:[ ]*[a-zA-Z0-9_]+");
	RegEx reg_export_inferred_type = RegEx("export\\([a-zA-Z0-9_]+\\)[ ]+var[ ]+([a-zA-Z0-9_]+)[ ]*:[ ]*=");
	RegEx reg_export_advanced = RegEx("export\\(([^)^\n]+)\\)[ ]+var[ ]+([a-zA-Z0-9_]+)([^\n]+)");
	RegEx reg_setget_setget = RegEx("var[ ]+([a-zA-Z0-9_]+)([^\n]+?)[ \t]*setget[ \t]+([a-zA-Z0-9_]+)[ \t]*,[ \t]*([a-zA-Z0-9_]+)");
	RegEx reg_setget_set = RegEx("var[ ]+([a-zA-Z0-9_]+)([^\n]+?)[ \t]*setget[ \t]+([a-zA-Z0-9_]+)[ \t]*[,]*[^\n]*$");
	RegEx reg_setget_get = RegEx("var[ ]+([a-zA-Z0-9_]+)([^\n]+?)[ \t]*setget[ \t]+,[ \t]*([a-zA-Z0-9_]+)[ \t]*$");
	RegEx reg_join = RegEx("([\\(\\)a-zA-Z0-9_]+)\\.join\\(([^\n^\\)]+)\\)");
	RegEx reg_image_lock = RegEx("([a-zA-Z0-9_\\.]+)\\.lock\\(\\)");
	RegEx reg_image_unlock = RegEx("([a-zA-Z0-9_\\.]+)\\.unlock\\(\\)");
	RegEx reg_instantiate = RegEx("\\.instance\\(([^\\)]*)\\)");