Silly me, I had forgot to the 'repack' the 3x3 grid I had edited.
This is the new download link:
https://www.mediafire.com/?vq414s3rvs09i4l
The folder you should select when rebuilding the terrain is named 'Repacked_W005N049'.
...and this is the full GWX terrain package (Warning: large download!):
https://www.mediafire.com/?yvwyx6py17uy7gx
Sorry for the inconvenience, and I hope you will enjoy this time
