Hi Rowan,
I never spoke about " the v-ray material".
And, in v6.0 RC1, the CoronaDistance map warning message error is fixed.
By the way, try these steps:
(1) open the attached scene and render it in 3ds Max (v6.0 RC1). Everything is fine.
(2) Now export the scene and render with the Standalone version.
(3) We can see the red warning of the CoronaDistance (nice fix), but the plane is "white" (no Bitmap or warning message).
(4) In 3ds max, change the Exposure (EV) parameter from -4.0 to 0.0.
(5) Export again and render with the Standalone.
(6) Now you are able to barely read the message : " Unsupported 3ds max Bitmap map", with the text is overexposed (see my previous image).
In conclusion, in this new message there is the same problem we had with the CoronaDistance warning message.