Cadence Allegro SBP15.5 - Exporting Gerbers

When I export the Gerbers using the post-processer, I find that some
layers are exported with incorrect information.

After a little digging I realized that the contents of the layers
listed in the post process settings spread*** do not correspond to
the actual layout. I can see this by right clicking on the post process
settings spread*** and selecting 'preview'.

A couple of the signal layers previewed actually duplicate the bottom
layer and the proper contents are nowhere to be found.

This really has me stuck and I would be very grateful for any tips as
to how to fix this.

Thanks

Chris Wilkinson

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