試試看:同時按住音量鍵+電源鍵,直到重開機為止。我的s6 Edge有類似的情形,用一用FB跟LINE的時候,返回鍵就會失效,要重開機才會回覆正常,上國外論壇爬文後得到http://forums.androidcentral.com/samsung-galaxy-s6/515688-s6-edge-back-button-folder-button-not-working.html