I have placed two additional vias on the thermal pad of the IC. Though the datasheet does not specify thermal holes, but I just did them to connect the pad with the internal ground plane (2nd layer). I am not able to figure out, why altium claims that there is an error and the vias are not connected. Why shall I connect the vias with extra track? Are not they connected through the ground plane? Please help. This happens many times with me.