I think, you must delete the pin numbers and refdes of symbol "$2I296" (what is double!). And than use the function "package".
But it is easier to assign in PCB with function swap gates and than make back-annotation.
Hope that helps!
I do not want to assign the gates in DxDesigner but I want to have a fully packaged design in DxDesigner without unused gates without going into pcb.
The solution was to set the slot to "none" with the command "pdbslot" for the gates with the errors as above.
Update 6 for EE7.9.5
As you seem to have answered this question yourself can you mark it as Answered so others may benefit from the solution.