adding I/O @ 1747-AENTR

I'm using a 1769-L19ER-BB1B. I'm trying to establish an SLC rack connected via a 1747-AENTR. I haven't connected anything to the laptop yet. Just doing the build for now. I right click on "Ethernet" in the controller organizer, add module, add the 1747-AENTR, set up number of slots and create it. When I go to add I/O to the SLC chassis, I right click on the new SLC chassis, click "add module" and my list is empty. I type some card data into the search bar in the window and nothing comes up. I can not create ANY SLC I/O slots.