"After analysing the submissions of all parties concerned and considering all elements brought before it, the FIFA Disciplinary Committee has decided to close the proceedings initiated against the FEF (Ecuador football federation)," FIFA said in a statement.
"The present decision remains subject to an appeal before the FIFA Appeal Committee." The FFCh lodged the claim against Castillo over "use of a fake birth certificate, false declaration of age and false nationality."
Castillo, 23, played in both Ecuador's matches against Chile, a 2-0 victory in Quito in September 2021 and a 0-0 draw in November.
Chile claim that Castillo, who represented Ecuador at both under-17 and under-20 level before graduating to the full national team, is in fact Colombian.
Ecuador are in Group A alongside Qatar, Netherlands and Senegal at the World Cup finals later this year.