Beginning in UltimateDR15, a new PRNT screen option will produce a NOTES page note saying why EIC is not being produced.
Under Items to Print at the bottom left of the screen, select EIC not being calculated? Mark this box, then see NOTES page in View mode for explanation.
View the return. Open the NOTES page and look for a return note explaining why EIC is not being calculated for the return.
You can also turn this option on globally from the home page of UltimateDR by going to Setup > Options > Form & Schedule Options and check the box Always show reason for no EIC. Click the OK button and view the return to see why EIC is not calculating.
Example of a return note explaining why EIC is not calculated: