I sent a dozen or so messages to current and former opponents at another site, suggesting they check out chessconquest. One told me he got a "bots not welcome" message when he tried to register. Assuming he wasn't trying to register with a script, what is his likely issue? He was located in China if that has relevance.
We use Google’s reCAPTCHA to prevent bots from creating user accounts. New players need need to check a box on the sign up form to indicate they are not a bot, otherwise they will get the bots not allowed message.
After some more back and forth, the individual has written: "When I click register, I can see a line for username, then a line for email, then two lines for a password and confirming password as you, but no recaptcha square." I asked about an add-on or extension for his browser that would suppress the recaptcha, but he says no and that he has tried different browsers.
Hope I have not caused issues here: I had missed your question about link. I do see recaptcha there, but .... 1) not seeing recaptcha was a different user, not me, and 2) going to that link in separate tab signed me out in original tab. Now I am seeing a different recaptcha (BritLink?), and a test on images for regular login, which certainly can be frustrating, and is why I worry about causing issues: others might also find that more involved recaptcha frustrating. Personally I wish you would revert.