ZBrushCentral

Cannot Load jpg Alphas

Hi, so I just tried to load alphas from the new Victor Marin pack Pixologic sent in an email.

I placed the extracted folder (all jpg files are showing fine in Finder, and open in image editors) in Applications>ZBrushOSX 4R8>ZAlphas.

In Lightbox, all the alphas show as question marks, and when I try to import via the Alpha menu nothing happens.

Where have I gone wrong?

Thanks in advance.