Problem: There was an error reading from the dongle.

This error indicates that the dongle memory has become corrupted. Either re-program the dongle with DinkeyAdd. Or use DinkeyRemote to solve this problem remotely:
Generate an update code to remove all the licences in the dongle.
Then generate another update code to add all the licences (and protection parameters) back into the dongle.
(yes, you have to generate two separate update codes in this way otherwise you will get the same error when the end user tries to apply the update code).