GI renders then is blackened

[gregsandor]

I've just encountered this on one tgd:  when I set GI detail off, the scene renders.  Adding GI, on render the GI pass is done, then the render chunks are all black.  What is this?

[gregsandor]

I've narrowed it down to one shader...

[gregsandor]

There was one greyscale (256 color) image map plugged in as a displacement function;  converting this to 16 million colors solved the problem.

Edit: maybe theres another BW imgage in there somewhere...  same problem occurs when I go back to the full scene...

Edit:  it is something to do with one of the default shaders...   it looks fine, but when it is attached the scene breake.  The reflective value is set very low; maybe that has something to do with it.
Edit:  replacing that default shader is the fix. 

[rcallicotte]

Why would that be a "fix"?  I mean I understand that is what brought you back, but this sounds like a bug.  Or am I misunderstanding?

[Matt]

Can you show me the settings for the default shader? (Remember that you can copy and paste a node clip directly into a forum post.)

There is a problem with index of refraction below 1, but I would expect that to affect the GI prepass too.

Matt