This is probably a really easy one. I am getting weird render artifacts around the edge of the transparent areas. See attached image. There is no glass in the window and it was rendered with a white envirnoment.Is this due to my anti-aliasing settings?. I am using Adaptive Subdivision Min=0 Max=3 Clr Thresh=0.1, Object Outline and Nrm Thresh unchecked. Antialiasing Filter= Mitchell Netravali. Thanks in advance for any help.
Did you save that out as a Targa? and then composite in the background? I’ve been having an issue like that with Targa files. Using tif or png solves the problem.
OR… if you go into photoshop before you comp in the background, make sure you “delete white matte” near the bottom of the layer menu.
That’s about as much as I can offer off the top of my head on a saturday night. 
or just render with black background should also sort the issue
Thanks guys worked it out, for some reason there was a pure white gradient ramp in the Max environment which V-Ray did not like. I deleted that and made sure the color was pure white. Rendered out perfectly, thanks again for the replies.