@buddhaauthor the folder is hardcoded into the build you’re using, and the person who made that build is the one who set it to something. It’s possible that the person who made your build forgot to change that “4” to a “5” (or actually to an empty string “”). But even though the value is hard-coded, you can still override it. See the “Custom config and cache folders” section
http://rawpedia.rawtherapee.com/File_Paths#Custom_config_and_cache_folders