opening catia files

Hi Guys.

New at this so please be kind.

We are getting models form a customer that they convert from Catia to stp, parasolid..... what ever we want.

Thier conversions don't always work well for some reason. Holes in the models on some, surfaces and solids mixed together and other issues.

I asked them to send me the original Catia file, which they did but for some reason my Solidworks 2016 says it processing but after30 min. of this still

nothing opens.

The Catia extension is ?????.catpart.

Any ideas>

Thanks Ken

SolidworksImport export