For newer Chamberlain garage door openers with MyQ the Insteon IOLinc can not send the necessary signal to the opener to open and close the garage door. One workaround is to wire a Chamberlain remote directly into the IOLinc instead of connecting it to opener. Of course, if you decide to modify your remote/IOLinc you should have a working knowledge of electronics--performing this mod is at your own risk and just because it works for this remote/opener doesn't mean it will also work for your devices.
Open the opener remote and attach/solder wires long enough to reach the IOLinc location to the points on the momentary button that close the circuit. You can see what points I used in the image at right. Be sure to verify the points on your remote with a volt meter as not all remotes are created the same.
After the wires are attached you need to modify to remote case just a bit to allow the wires to fit out. Use a cylindrical file or any tool that will cut through plastic without damaging the case too much. Be sure to clean up any residue shavings. Carefully place the remote circuit board back into the case and verify that the cutout is large enough to allow for the wires to move freely without rubbing or damaging the wire.
Place the button cover back onto the remote case and carefully snap it closed ensuring the wires are not pinched. After the garage door remote is reassembled you can attach the wires to the IOLinc. With this setup you would attach the wires the the normally open N/O connection on the IOLinc. From this point whenever you use the IOLinc it will trigger the remote to open the garage door.
If you have any questions or corrections please let me know.