Running 6.0.1 Marshmallow. I have deleted my music folder on the internal storage area, mounted a 128GB SD card and established a music folder on the root of the SD card. I copied 14.1GB of 320bit .mp3 files to the music directory on the SD card via. SS USB using MTP. ( 6hr process) Using Premium version of Rocket Player these files showed up properly but when I tried to play them the player acted like it was intermittently fast forwarding through the songs and them would automatically fast forward to the next song and then do it all over again. The player acted like it was schizophrenic. Fearing a bad SD Card or inadequate SD bus I created a test directory in the root of the internal storage and copied the song to that location. The player exhibited the same behavior. I decided to reboot the phone and when I did the music folder on my SD card diapered. All my files had were moved to the LOST.dir and renamed by number. I though this might be related to the fact that I copied all 14.1gb down in a single lump and tried it again with a much smaller batch of files. The same behavior occurred. On the first try files were identified and Rocket Player operated schizophrenically. After reboot SD Music directory was gone and all files were moved to the LOST.dir. I never had this problem with my Android 5 phone. I am not very literate with Android and could use some help understanding how to correct this. I just want to listen to my music!!!! Thanks for the help.