This error message appears when a Corona Light Material ( Max | C4D ) with its "Emit light" option enabled is used in combination with Corona Pattern ( Max | C4D ). This is currently unsupported and the object using Corona Light Material will render black (be it the base object or the pattern node).
The cross-shaped object is using a white light-emitting Corona Light Material. It is then used as a pattern node to create a pattern on top of the plane object.
- Use a Corona Physical Material or a Corona Legacy Material with self-illumination enabled to create a self-illuminated Corona Pattern.
See: Should I use Corona Light material or Self Illumination to illuminate my scene?
- Disable the "Emit light" option in the Corona Light Material. It will stop casting any light into the scene in this case, but will not render black any more.