Numerical Innovations - Help Center

Looks like a good product which may do what I need. However, I have a problem with importing apertures from folder with 274d Tango files. I can import the apertures successfully (.rep file in Tango), but when the board files are loaded, all of the pertinent apertures are deleted.

I'd recommend that you load those gerber files using "AutoLoad" (located in menu: File | Import | AutoLoad...).  FAB 3000 "AutoLoad" will automatically load all files from a directory, plus determine which aperture rules to use.

If the gerbers appear to be loaded without apertures (i.e. there is no width on the traces, flashes, etc.) and you receive warnings during import, than you should create an aperture rule for FAB 3000.

FAB 3000 comes with an "Aperture Rules Editor" to read most aperture lists and you can also customize it to load any aperture list.  FAB 3000 ships with about 35 built-in apertures rules, however it appears your "Tango" aperture list is not included.  It is very easy to create a new FAB 3000 "aperture rules" that is specifically designed to load the Tango style aperture lists.

Here's a link from the FAB 3000 User Forum which you should find helpful.