Reply to Version mismatch?

I have recently discovered a site that gives free traktor remix sets and 3/4 of them are great and very fun samples to play around with but occasionally I get the odd remix set that comes with a message saying "error on importing content set, version mismatch" This is when I try and import slightly older files, surely traktor would allow you to import older "remix sets" ??? anyone know a way to fix this?