Make sure pop-up blockers are turned off on your browser. This often is a problem for users that can't seem to add content.
Ocast works for almost every type of browser. Unfortunately, anything after Internet Explorer 9 doesn't work. Try changing to Chrome, Safari, Firefox or something other than Internet Explorer.
Can't edit or add content on your page? This could be that your permissions don't allow it. If you are listed as an end-user on the profile you will not be able to update content.