..

-

fail-safe variant: a document can be perfectly valid, but not "producing any effect" i.e. unusable as a proof of whatever it is to be proved.

just one example: a perfectly valid ID card is usable in the country where it was issued but may be totally useless (= "ineffectual") in some other country where only a passport will do.

Or: a perfectly valid "land title" from another country is "effectual" unless accompanied with an official transalation.