ScottR_UK

I have been the page https://ultimaker.com/en/resources/44677-maximum-build-volume-ultimaker-2-plus-ultimaker-3 and followed the instructions. But I cannot get a 195 x 195 square to slice on an Ultimaker 3 Extended using Cura 2.7. I downloaded the profile and use that - it does not work I follow the detail to set manually - it does not work What am I missing? The spec sheet states Dual material: 197 x 215 x 200 mm as the maximum build volume.