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.
Chan urrainn dhan deasaichear HTML Framesets a dheasachadh no duilleagan anns a bheil frèamaichean ion-loidhne. Airson Framesets, feuch ri duilleag gach frèam a dheasachadh 'na aonar. Airson duilleagan le iframes, sàbhail lethbhreac dhen duilleag is thoir air falbh an taga <iframe>.