I'm not sure if this is the reason and hopefully someone who knows more about it can chime in with a better idea but it might be because of where one or more of the players lives. The game may be using your location to prevent you from playing "Skins" games because it is not technically "Legal" where you live. I believe that the skins games are legally considered a form of gambling as you are wagering "credits" on each hole and online gambling may not be available where some players live so it blocks them.
Also, did you request to have WGT change your flag from the Union Jack to the St G's Cross? Funny as it may seem, this might be the issue too. I believe there are a few glitches when you have your flag manually changed by WGT.