As it turns out the my gerber files don’t have the mask (generated from SolidWorks PCB 2017). I am trying to figure out how I can take the solder paste layer and make a negative of that so I could create the mask. Do you know if this is possible?
Yes, ACE allows you to edit anything - so you can definitely make the reverse of a paste layer. Here's a quick movie showing me take a paste layer and generate a "negative".
Note: There are many different methods to create this negative image -- I just performed the first idea that came to mine.
Note: Our product FAB 3000, has the same conversion abilities (as ACE 3000) plus the ability to genre mask layers and more editing capabilities.