Pretty sure it's hardcoded. Basically what it does is creates a System_ReturnToBlockland folder with tiny content (will not affect you much), I don't know what exactly that's about. You should be fine when hosting now. If you crash, try starting blockland again (do not host) and put this in the console: trace(1); disconnect(); trace(0);, then close blockland. This will tell us what other add-on is causing this.