How to reproduce:

1. Open attached project
2. Open scene test2.unity
- The scene contains a variety of cubes in different colours positioned on a single plane. Every object is set to Lightmap Static (except the Directional Light). The directional light Baking mode is set to Baked. In the Lighting/Scene window the ambient source is set to colour and precomputed GI is disabled. Compression is disabled and Final Gather is enabled. There are also custom Lightmap Parameters.
3. Try changing the General GI directionality modes.
- Note how when the mode is set to Directional, the edges of some cubes appear to be glowing.
- If a sphere is added (lightmap static enabled) and given a material, it also appears to have "edges". The effect is less pronounced in non-directional mode, but it is still present there.