Numerical Innovations - Help Center

In order for this function to work, how do you define a negative layer type? I watched the video but could not figure it out.

I right clicked to assign a negative layer but still could not convert negative plane.

It is recommended by the Gerber standard to keep all files positive and try to limit the need for negative layers.  The command "Convert Negative Plane" will take a negative gerber layer and make it positive.  This command requires 1 or more layer types is defined as "Neg. Plane".  If you wish to use the "PCB Border" as a boundary, please make sure that is defined.

Here's a tutorial movie showing me convert two negative plane layers into positive plane layers.  I am just using the FAB 3000 sample Gerber files found in he folder .../FAB3000v7/examples/274X.