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Two inexplicable DFM errors

Two errors that I can't figure out:
142 double drill hits 

1 power - ground short

The .txt drill file looks fine.

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142 Drill Hits

When viewing the workspace file, there's definitely duplicated drill files.
The drill file you supplied does not have duplicated holes.  So perhaps there was some editing/copy, merging layers; because there's definitely 3 drill hits for every hole.  

1 power - ground short

I will review the Power/Ground next - however you're using a "negative" layer which is typically not recommended and more difficult to follow for netlist extraction/dfm checks, etc. (in fact negative gerber files have been deprecated in the gerber format).  
To resolve the issue, I would use the command  (menu: Fabrication | Convert Negative Layer...) to convert your ground layers to positive and then perform all checks, etc.  In fact when you send these files out for manufacturing, the fabricator is going to convert your negative layers to a positive layer.   

When I run the DFM Check again using positive layers there is no Ground/Short error mentioned anymore.

Avoid Negative Plane Layers:

Everyone from CAM tools to PCB manufacturers' have troubles with Negative metal layers - because they are incomplete.  Here's the direct quote from the Gerber format specifications manual:
Note: It is recommended output copper layers in positive. Power/ground planes in negative was introduced in the 1970s and 1980s to get around the limitations in the vector photoplotters then used. There is no longer any reason to use them, and they have a problem: they cannot not define how close the copper gets to the outline of the PCB.
Here's a sample PCB manufacturer suggesting to stay away from Negative metal layers,

To goal of FAB 3000 is to prevent any troubles with properly manufacturing your PCB designs.  Every board shop in the world will have to manually edit negative layers before manufacturing -- which can introduce unintended consequences  that you may not be aware of (from their editing of your plane layers), until after the boards are made.

Thanks again, for sending the sample files.

Best regards,


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