Unity 5.5 I can no longer use hdr or exr file for light maps.

Hi all

So I decided to try 5.5 today, specifically for the hdr improvements, I have read about. However, on opening a new scene, dragging an hdr image into unity and changing the texture type to a light map, it seems unity will not recognize these files as light maps anymore. I cannot drop them into the slots where lightmaps would go. Am I doing something stupid? previous when I changed to lightmap I got the option to choose if it was a cube map etc, I no longer have that option.


Any help would be massively appreciated.

thanks

Will.