When you open SellerDeck EPOS, you may see the following message:

"Error Reading DK2 dongle"

This means your blue Deskey EPOS Dongle has stopped working. The Deskey dongle looks like this:

To fix this, please see below:

1) First, try plugging the Deskey dongle into a different USB port on your PC. Allow a few minutes, then try opening SellerDeck EPOS again.

2) Try installing SellerDeck EPOS on another computer, and see if the blue Deskey dongle works on that PC. If the dongle does not work on another PC, that would suggest that the Deskey dongle is broken or faulty. In this case, please contact SellerDeck sales.