So I've just had the same problem twice in two different threads where it says "an unexpected error occurred please try again" every time I try to respond to a thread with a post with a link in it. The second link I tried to share was a Mumsnet link to a thread so I don't think it's the content of the links that's the issue here. Is it just me? I'm on a MacBook Air M1 on Google Chrome.
Edit: It's mysteriously working fine now. Sorry. IDK what's going on. 🤔