Composer cannot edit HTML framesets, or pages with inline frames. For framesets, try editing the page for each frame separately. For pages with iframes, save a copy of the page and remove the <iframe> tag.
Amsuddes ur yemir ara ad yeẓreg tagrumma n ikataren HTML, neɣ isebtar s ikataren s srid. I tagrumma n ikataren, ɛreḍ taẓrigt n usebter n yal askar i yiman-is. I yisebtar s ikataren, sekles anɣel n usebter sakin kkes taṛekkizt <iframe>.