Greetings,

The attached MWE combines 12 images in  a 3 by 4 grid; with horizontal and vertical spacing set by setupcombinations.  

I have two questions. First, can someone please tell me why the vertical spacing is not applied between the first and second and third and fourth rows?  Second, why, If I try, e.g.c 15 images, does  ConTeXt complain of a missing left brace. More generally, my mwe failed with an odd number of images, but succeeded with an even number.

Thanks.

With kind regards,