hi. your profile is a bit thin, I’m gonna suppose you have at least SU pro. what version do you have ? is it the old classic licence or the subscription ? are you still using an older mac sierra mac ?
what version is your correspondant using ?
(please add these infos to your profile so we don’t have to grill you for it later again :). click on your icon top right, then the silhouette, then profile)
you have two choices. they can re-save the file in an older layout version, or you can update your SU.