You cannot click the OK button on the login page, it is disabled.

Cause of the Problem:

Probably a Firewall that prevents it from properly running java scripts or using the plug-in.

Solution:

• Check for a firewall or antivirus program:
• Restart the login flow:
  Close all the browser windows you have open, and click the URL from the invitation.

  Please Note: If you reached the session through a panel company website, closing your browser might result in you not being able to reach the session again. If you wish to continue your participation in the session, please copy the URL line before closing your browser and then reopen it and paste the link to the new browser. The link to the session may also be found in your browser's history.