What do I do to get it working again? Thanks.
What do you mean by "it" - the food coloring cartridges? If so, I would just replace them. They do dry up if not used for a while.
I just bought a printer for edible use and haven't taken it out of the box yet (in process of creating craft room), But I googled "how to clean edible printer" and quite a few articles and videos came up. Sorry I'm not more helpful. Hope you can get it working again.