[GUI] Not loading files in save/load windows when "unmappable characters" present in folder

A file inside the folder where I want to save/load a model is called "ws22/23". When trying to load/save a model in there, that window starts loading and freezes while doing so. The rest of the GUI still works.
Error below: 

Exception in thread "Basic L&F File Loading Thread" java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters: /home/xxx/WS23???24