One of my Son's called me and said with his new Samsung Galaxy S7, he could not select ringtones and notifications. Said the list of Samsung provided ringtones and notifications was missing. Where the list for each would have been he found a blank screen. Took a little thought on my part but I figured out the reason for this issue. It was because when he installed the very popular and highly recommended, ES File Explorer Manager https://play.google.com/store/apps/details?id=com.estrongs.android.pop&hl=en he made the lets call it an incorrect choice when he opened the newly ES File Explorer app and it asked him to select the app the S7 was to use as the default app. He choose ES File Explorer when he should have selected the other choice offered which is the built in S7, OS app to use. SO, easy fix was to quickly/easily uninstall ES File Explorer Manager and this time not to select ES File Explorer when asked what app to use as default After the re-install, all the ringtones and notifications that come with the stock S7 were visible in the lists and selectable. For the record... I could have had him to to settings, Applications, Application Manager and then scroll down until he came to ES File Explorer. Once there he would need to click on the word Storage and then click on delete data. Doing this would have given him the option pick the default app that is necessary. I chose just to tell him to uninstall and then reinstall and making the correct default choice..