PBR Shadow shader error

Hi!
PBR Shadows stopped working just now (with the latest updates I think)
It shows a shader error  ERROR: 0:1137: 'z' : vector field selection out of range
When shadows are enabled on a PBR material.

Test case:
http://www.babylonjs-playground.com/index.html#1MJ2U8#7

This works with 2.5 and worked in the morning.

I hope someone knows what happened