If you have a WAGO Bus coupler on Ethernet/IP that has only inputs, no outputs, you are going to lay out your assembly instances differently then the WBM states.
In the above image, you will see that all of the AO and DO lengths are zero. If you ever run into a case like this, you are going to want to use Assembly Instance 198 as your assembly instance for your outputs with a length of 0. Assembly Instance 198 is for Inputs only. Please see below for a snippet from the WAGO manual: