The possible reason for this problem could be that your Firewall(from Windows or an antivirus) is blocking the software. Be sure to allow the software through Firewall. Moreover, it is possible that the capcha server is down. In this case you should probably try again later. If this didn't solve your problem, I suggest you contact the developers through the following official web page.
You can also check the following link for a tutorial on how to join chat rooms using this software: