Any chance you can tell us the version of the Connect Add-in you are trying to install? How about your OS and browser you are using?
Thanks for the reply!
This is the page from where I try to complete the installation by clicking on "install now"-button to the right: http://na1cps.adobeconnect.com/common/help/en/support/meeting_test.htm
I am using google chrome. What is "OS"?