Google Wifi IconFix:

For the primary:

Power up the WiFi puck with the network cable plugged in, but don’t go into the app.  Look on the bottom for the network name and password (starts with “setup” for the network name).  In your phone settings, add the setup network and use the password near the square QR code.  Then go into the Google WiFi app and start the setup process for the primary puck.

For a secondary puck:

Plug in the puck (with no network cable) and add the setup network from the bottom label.  I had to then reboot the puck (unplug and then replug power) and then go back to the Google WiFi app while the puck was rebooting, to allow the “search and find” part of the app to work.  Otherwise, it would go directly to “activate mesh” and fail.

Analysis:

It looks like the app has a problem making the setup network stick.  Once the phone has the setup network added, the setup process seemed to work.

Hopefully this helps you, as it took me 5 hours to come up with this solution.  I was about ready to throw in the towel.  However, note that once you get it setup, the system has been really nice to have.

Since I’ve completed the install, the Google WiFi mesh network has been working really well.  I’ve played network games off of a mesh point, made Verizon Wi-Fi calling calls on an iPhone throughout the house (and off of each of the points).  It has been pretty bullet proof.  If only the installation had been easier.

Hope it helps

–Ben

Sources:

R Pearson from Google WiFi Help Support boards.