I am having a problem with my net check where, though my connections are all labeled with net GND, and the ground plane is also labeled net GND, a net flag is being raised. I can't seem to find a solution for this problem. The connections seem to be connected correctly, but something is wrong. Are the connections supposed to be made using vias? Please help.
Will adding just vias with the same net name connect the top layer to the copper pour in the bottom layer? I tried doing that and it still flags as an error. I have tried connecting all the pins for GND together and that gets rid of the flag, but I can't figure out how the copper pour works with the grounding system.
@andyfierman Will adding just vias with the same net name connect the top layer to the copper pour in the bottom layer? I tried doing that and it still flags as an error. I have tried connecting all the pins for GND together and that gets rid of the flag, but I can't figure out how the copper pour works with the grounding system. I'm new to this program and to PCB design.
@andyfierman I figured it out now. Made a common ground on the bottom layer, then brought all GND connections to that pour and ended the connections with a via. No more errors! Thanks!
Brand new interactions and interfaces. 
Easy to use and quick to get started. 
Looks like the ground flood around the GND end of RSEL isn't connected in to the rest of the GND net. It is cut off by the tracks from the high end of CIN to U2.
You need to do something like add a GND plane on the bottom layer and add a few vias to connect to the bottom end of RSEL and the rest of the GND on the top layer.
I also suggest you review your layout in the light of:
http://www.ti.com/lit/ds/symlink/tps62143.pdf
http://www.ti.com/lit/pdf/slyt614
and similar documents for U2.