Make a back up of tom tom to have less probellems and dount let your sd card get lossed

I red cross usually indicates an SD card problem.
With most tomtom's usually removeing the SD card and powering up will resolve the issue.

If not then a HARD reset without the SD card may be called for.

If it does prove to be an SD card error then formatting in a proper card reader using FAT32 as the file system and then copying the files back over from the tomtom usually does the trick.

Or format and restore from a back up to the card. can work too.

It may also mean that a files might have been deleted or become corrupted.

This problem is due to the memory card not containing the TomTom application or map. To update the application onto the memory card, Connect the device to your computer. Open the TomTom Home application. Click on 'Update My Device'. This should then install the application onto the SD card. Alternativly, you could perform all the steps above without the SD card in the device, this will install the application onto the internal memory. Note: you may also need to install your maps, voices, etc after you update.

I saved the map on to my computer from the tom tom in Tom Tom Home and installed it on to a new SD card and now it working perfectly. I bought a 2mb SD card for £6.70 put it into a card reader and connected to computer and installed map and it gave me the instructions to put into device (Tom Tom) and switch on to connect then off and back into card reader to finish. Then I disconnected device which is important to do by the way put the new Sd card into Tom Tom and it is workink perfectly. I hope this help others who have problems.

TomTom Support
or here

TomTom Support

If you have TomTom that have the slot for SD card, then it should accepted the SD card. The instruction for how to use the SD card is simple, but it is hidden in the TomTom Home, that's why it's difficult to find it. Below are the instruction how to use the SD card.

1. Format the SD card (FAT32) and do not stick the SD in the slot yet
2. Run Backup (connect TomTom device to computer)
3. Disconnect TomTom from computer and turn off
4. Slide the SD into the slot and connect TomTom back to computer (choose "yes")
5. In the TomTom Home menu, Choosen Backup & Restore >>> and choosen Restore

TomTom Home will add all applications to the SD card. So the internal memory still have the applications and the SD card also had the same applications. Everytime you slide the card in, TomTom will automatic detect and use it as its primary storage, if it not detect, you can go to the device menu and pick the device to connect to.
Whenver you take the SD card out, then TomTom will use its internal memory.

Hope this helpful