My Printer Ruined My Ruin

This is the Medieval Church Ruin from Printable Scenery. It's a companion piece to a non-ruined medieval church of the same design, and I got it for cheap as part of a bundle. It's modelled for 28mm miniatures, but I've printed it here at 50% for use with 15mm figures — though it's a wee bit small, and 60% would be better.

Alas, my printer's layer-shifting chose this time to reassert itself, so the ruin is even more ruinous than it really should be. It's still usable as piece of wargaming terrain, but a stone structure this wonky would be so unstable that it would come down with a sneeze.

I am working my way through all the possibilities to diagnose the source of the layer-shifting, but it's a long slog. It's one of the most infuriating 3d printer problems, because it can hide itself until exactly the worst possible time, and then spring forth again like the monster in a horror movie that everyone assumes has been destroyed.

I'll probably reprint this model after I've got the printer running smoothly again, assuming I ever do.