[Q] D415 TWRP Backup Failed? topic

I recently unlocked my bootloader and now have access to TWRP recovery, but whenever I try to backup, it shows "backup failed" and has a button at the bottom allowing me to reboot (to the lockscreen, homescreen, etc.)

I am trying to flash CyanogenMod 11 onto my device but first I would like to do a custom recovery before I do so, any help on that?