I’d be curious what happens if you edit the file and replace the word “EdgesGeometry” with “BufferGeometry”. Either way, it looks like support is just missing in ObjectLoader, and would need to be added there. Might be worth filing an issue on GitHub for this one, it sounds like a reasonable idea.
After trying to make it work without touching three.js source code eventually I found that in ObjectLoader.js there is switch statement which has almost all geometries but not EdgesGeometry. Added case with EdgesGeometry there and it seems to be working fine, still testing. I wonder why it wasn’t there in the first place since it is not breaking anything. Anyway thanks @donmccurdy, if my tests pass I will open an issue or PR on Github.