From your image you appear to have 3 execution pins entering the collapsed (“Get Selected Data Table Row Names”) node. but there only appears to be two arrays coming out. From what I can tell you should have a third array output connected to the Empire Set input on the select node right next to it.
This will fix it the card editor but not the issue you were seeing with the error.
What I can see in your Get Card Data function, your new set has been added below the Empty Card set execution flow. The function at the moment will return before it gets to your new card set because the empty set calls the error you were seeing and return without ever looking at your new set. If you go into the Card Set enum, and move your new set above the Empty set option, this should hopefully fix the issue your seeing. Alternatively you can change this function to be like the example I suggested in my last reply and this shouldn’t be an issue anymore.