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Are you using an SD card inside your smartphone formatted to exFAT? This could cause the issue you're describing. exFAT is the format used by default with many SD cards or 32 GB and above. (you can determine the file system of a microSD card is to mount it in a USB adapter and view its properties using a PC)
If you're not able to format your SD card to FAT32 too or use it with your phone, please contact Customer Service so that they can look into it and forward the required details to out technicians.
Before installing TomTom, eject your SD card. Then run TT and download the map of your choice. Finally, re-insert your SD.
........... I have proved this many times on Galaxy S3, Galaxy S5, Moto X Force, Moto X Style, Galaxy Note 10.1, Galaxy NotePro 12.2, etc., on a variety of different Android versions, both stock and custom... need I go on?