If the Octatrack boots to DEMO mode even though the CF card is inserted, this is likely caused by a damaged CF-card reader pin list. The Octatrack is not able to register that a card is inserted when one or more pins are bent or missing.
Remove the card, and look carefully inside the slot to see if the pin list looks intact. If it's hard to see, you can also take a photo and enlarge the photo for easier viewing.
If the pin list is damaged, please contact Elektron support.
If the pin list is intact, then it is possible that the CF card is defective, and we recommend trying a different CF card.