AutoCAD 2010 :: Not Recognizing PAT File?

Our new employee is trying to do a custom hatch of a stone pattern, but when he selects it, he gets a message saying it's invalid. I had him copy over the entire PAT folder that I use and tell his support directory to look at it. It works when I use it on my computer. So far none of the other custom hatch patterns give him an invalid message, just this one.

I know he's working on drawings that another ex-employee started. He used a whole different set of PAT files for some reason. I think when we were looking for downloadable files and just used whatever he found. And this new employee is working on the computer of someone that is no longer with the company...so it's impossible for me to find out who did what. Also, I don't know if it makes a difference, but I (and 2 other people) have Architecture 2010, and the rest of the employees have AutoCAD 2011. I don't think this is an issue because no one else seems to have this problem, and like I said before, all the other hatch patterns work.

The thing that doesn't make sense to me is that I'm pretty sure this pattern is a standard custom hatch, because it's found in my "AutoCAD Architecture 2010/support" folder, as opposed to my "ACA 2010/enu/support" folder. But when I go into his system, he doesn't have any of those patterns in his similar folder.