The "Can't Agree to Terms" error on CS.RIN.RU is a defensive mechanism triggered when the forum cannot verify that you have viewed and accepted the rules. It is almost exclusively caused by ad-blocking software preventing the agreement checkbox from loading. Whitelisting the site or disabling the blocker temporarily will resolve the issue.
This error is a common source of frustration. Below is an informative breakdown of why this happens and how to resolve it. cs rin can't agree to terms