whenever i place a via to connect the top and bottom ground planes on a pcb and click update it disconnects the copper pour from the via. what am i doing wrong?
Farley in the above post has given you a good run through.
One thing to consider is to place all your "new" vias to the side of your design first. Then connect them to the appropriate net (by following Farley's post above), then shift them to where you want them, then repouring the existing ground plane.
You can hide the ground plane (or any copper pour) while you do this if you wish.