Philips Android doesn’t write to ext. USB

To prevent always writing in my TV’s (55PUS8601) internal flash memory, I connected an external USB 3.0 harddisk, formatted in NTFS.

With a filemanager app, my TV reads and writes to the USB harddisk without problems. Once I’m using Kodi and I try to write to that disk, I get the message: “Check your write permissions on the choosen location and verify if the new folder is valid” (translated from my Dutch Kodi).

Connected another USB stick, no succes.
Connected the same harddisk on my HiMedia Android box, everything works perfectly.

How can I get rid of the error message on my TV?

Thanks,
gert