Original Prusa i3 MK3S+
https://help.prusa3d.com/downloads
After upgrading to 3.14.0 the printer was complaining that the g-code was sliced for a different printer. I found this article that recommended upgrading the printer profile settings in Prusa Slicer to MK3S +MMU3, even though I was using an MMU2.
Still need to tension the belts they look loose – https://help.prusa3d.com/article/adjusting-belt-tension-mk4-s-mk3-9-s-mk3-5-s-mk3-s_112380
