I'm having a problem with stitching vias. I have a device (an RF oscillator) which is packaged in a metal case with four mounting tabs (right-angle metal with a hole). My decal has four terminals for the four tabs and I've added copper under the device which is associated with one of the tabs (All tabs connect to ground).
I tried adding both copper and copper-pour regions(assigned to ground) on the bottom of the PCB, but when I try and add stitching vias, I get a via placement violation. I can turn off Design Rule Check, but I would like to know how to do this properly so I don't get an error.