Sometimes, the extruder will start clicking and the filament will stop feeding. This can be a couple of things, I usually start my diagnosis on the hotend, as that is most often where I have found the problem(s) to lie. In my experience, it usually means that I have some type of clog on the hotend side that needs to be cleared.

To clear things up and get printing again, I usually do a cold pull. Then I snip off the first 25mm or so of the filament to make sure that I’m not reintroducing some contamination to the hotend. Then I heat the hotend up to about 20 degrees hotter than my print temperature and make sure that I heat tighten all of the hotend components to make sure that there aren’t any gaps anywhere.