When this error message appears it means that the Ultimaker can't read the SD card. There are a few simple checks you can easily do yourself:
- Ensure the SD card is properly inserted in the SD card slot
- Try another SD card to rule out the SD card as source of the problem
If this doesn't resolve the problem, there's a chance that the problem is caused by the Ulticontroller electronics. In this case we advise you to get in touch with one of our local support teams for further help.