Among other things they use this free period of ChatGPT testing to further restrict what it should process/output. Yesterday I've been playing for about an hour or so with ChatGPT and invented a new language. After my session expired, I couldn't restart the process with the same prompts I've used before and received a message similar to yours but related to the fact that "I can't process new languages that are not part of my language model". Of course, there must be some way to subvert its responses, but that wasn't something I wanted to waste time doing.