Wayne,
I'm running 6.6.7 and the Check-In is still there though we don't use it.
There used to be a screen on the AC website that listed the details of each version but recently that was removed and squirreled away. Now to access that info you have to click on the Client Portal tab on the AC website home page. Then scroll down and in the teal blue box click on "Click Here to download the latest version of Amazing Charts." If you scroll to the bottom it lists the details of each of the updates from 6.5.6 to 6.6.7. I would never have found it in a million clicks without help from tech support.
John
