Lightmaps Suddenly Broken

Hey there,

Not sure if anyone has a quick solution for this, but my lightmaps suddenly seem to be messed up beyond recognition. Emissive textures are doing all the lighting, and were working fine (first image) - until they popped over to where they are now (second image). This was not on a lighting bake, mind you - it just happened while I was doing some script work.

Anyone seen something like this before?

I've tried toggling the Generate UV Lightmaps on and off, and I've ensured the lighting settings are exactly the same as the working scene.

Thanks in advance!

Unity 5.5.3f1