Have Koba, Australian build, have had trouble installing personal startup image and Display off image. The unit will not recognise the USB with the folders. Have had the Toyota workshop manager with his laptop unable to work it out!
Thanks Chow Chow
Not sure if you have tried different file types/formats yet, but that's a good place to start. My second suggestion would be to try labelling the folders you're pulling from as StartupImage and DisplayOffImage. Sometimes infotainment systems can be a little particular pulling files from USBs requiring exact names/capitalizations.