On Android, if you receive the error Scan failed on [/] with error code 13 when using SyncBack Touch then please change the directory that is used on Touch for the profile, e.g. change it to \sdcard\
Error 13 is an access denied error. Changes since Android 7.0 (Nougat) mean applications no longer have access to the root directory (\). Because of this it is recommend you set your Touch directory to \sdcard\
If you need to access the device's external SD card then you may use the %SBT_EXTSDCARD% variable in the profile's source/destination directory instead.