I've not heard of it; well actually I think there were two odd versions many years ago called PC-Dmis Basic and (possibly) Premium, but I though they'd died a death many years ago.
Do you mean that the default clearance cube toolbar that was in older versions is no longer in the context menu in the toolbar? Or that it's just hidden?
Right click on the toolbar like in this picture and select it. If it's not there just click customize and create a custom toolbar with the corresponding clearance cube options.
