Broken skeletal mesh

http://runnzell.com/brokenMesh.jpg

Link above. This happens for every skeletal mesh I try to import into the engine. They all used to work fine (back in 4.3 or so) but now they are broken, no matter what settings I try to play with in the importer dialogue.

They open fine in Maya, but even when I re-export them from Maya, they import this way in UE4.7.3.

Any clues to what might be causing it?