Answered: What is causing these seams?

Newbie alert!  I am a programmer, so I'm well out of my depth with this stuff, however I want to put together some basic models using MODO Indie 10.0 and Quixel Suite 2 (2.2.1PR3) and have done a quick test.  I am getting the following seams and I wonder if anyone can suggest what the issue is?



This is what it looks like in Unity (note the dull gold edges, but that's another issue...):



Here is my complete Quixel project (Dropbox 53MB).

Thanks in advance for and light you can shed on this!