Problems adding Flex-I/O in Logix5000

I am trying to add a 1794 - 120V AC Input module to an existing flexbus connection and when I attempt to add the module using the Module Discovery option in the controller organizer window, I see all 6 existing modules shown grayed out (Thermocouple input (2), Analog output (3)and VHSC). In slot [06] I see the 1794 - 16 Point 120V AC Input module grayed with the message flag, "Device cannot be added because there is no room left in the chassis or bus".

Other flex racks in the network have 7 cards and this one would bring the total in the rack to 7.

Anyone have any idea what is preventing me from being able to add this card in Logix5000?

Thanks!

Your adapter chassis size is set for 6.
You need to change it to 7 or 8 before you can add extra modules

I checked, it is set to 8.

Post your ACD file here and RSlinx flex module screenshot

BTW, you can't add 1794 modules online, all changes must be made offline and downloaded.

Gotcha, I was under the impression I would add modules online. That may be my issue. I will try to add the module offline and download.

Working fine after Offline add and Download. Not sure why I received the error message that I did though. Thanks for the help!