### 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)

valid = valid && test_conversion_gdscript_builtin("\tmove_and_slide_with_( a, g, b, c, d, e, f ) # Roman", "\tset_velocity(a)\n\t# TODOConverter40 looks that  in Godot 4.0 is float, not vector like in Godot 3 - previous value `g`\n\tset_(b)\n\tset_floor__enabled(c)\n\tset_(d)\n\tset_(e)\n\t# TODOConverter40 infinite_inertia were removed in Godot 4.0 - previous value `f`\n\tmove_and_slide() # Roman", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("remove_and_slide(a,b,c,d,e,f)", "remove_and_slide(a,b,c,d,e,f)", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("list_dir_begin( a , b )", "list_dir_begin() # TODOGODOT4 fill missing arguments https://github.com/godotengine/godot/pull/40547", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("list_dir_begin( a )", "list_dir_begin() # TODOGODOT4 fill missing arguments https://github.com/godotengine/godot/pull/40547", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("list_dir_begin( )", "list_dir_begin() # TODOGODOT4 fill missing arguments https://github.com/godotengine/godot/pull/40547", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("sort_custom( a , b )", "sort_custom(Callable(a, b))", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("func c(var a, var b)", "func c(a, b)", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("draw_line(1, 2, 3, 4, 5)", "draw_line(1, 2, 3, 4)", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\timage.lock()", "\tfalse # image.lock() # TODOConverter40, Image no longer requires locking, `false` helps to not break one line if/else, so it can freely be removed", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\timage.unlock()", "\tfalse # image.unlock() # TODOConverter40, Image no longer requires locking, `false` helps to not break one line if/else, so it can freely be removed", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\troman.image.unlock()", "\tfalse # roman.image.unlock() # TODOConverter40, Image no longer requires locking, `false` helps to not break one line if/else, so it can freely be removed", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\tmtx.lock()", "\tmtx.lock()", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\tmutex.unlock()", "\tmutex.unlock()", &ProjectConverter3To4::rename_gdscript_functions, "custom rename", reg_container, false);
	valid = valid && test_conversion_with_regex("extends CSGBox", "extends CSGBox3D", &ProjectConverter3To4::rename_classes, "classes", reg_container);
	valid = valid && test_conversion_with_regex("CSGBox", "CSGBox3D", &ProjectConverter3To4::rename_classes, "classes", reg_container);
	valid = valid && test_conversion_with_regex("Spatial", "Node3D", &ProjectConverter3To4::rename_classes, "classes", reg_container);
	valid = valid && test_conversion_with_regex("Spatial.tscn", "Spatial.tscn", &ProjectConverter3To4::rename_classes, "classes", reg_container);
	valid = valid && test_conversion_with_regex("Spatial.gd", "Spatial.gd", &ProjectConverter3To4::rename_classes, "classes", reg_container);
	valid = valid && test_conversion_with_regex("Spatial.shader", "Spatial.shader", &ProjectConverter3To4::rename_classes, "classes", reg_container);
	valid = valid && test_conversion_with_regex("Spatial.other", "Node3D.other", &ProjectConverter3To4::rename_classes, "classes", reg_container);
	valid = valid && test_conversion_gdscript_builtin("\nonready", "\n@onready", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("onready", "@onready", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin(" onready", " onready", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\nexport", "\n@export", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\texport", "\t@export", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\texport_dialog", "\texport_dialog", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("export", "@export", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin(" export", " export", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\n\nremote func", "\n\n@rpc(\"any_peer\") func", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, false);
	valid = valid && test_conversion_gdscript_builtin("\n\nremote func", "\n\n@rpc(\\\"any_peer\\\") func", &ProjectConverter3To4::rename_gdscript_keywords, "gdscript keyword", reg_container, true);