I'm having the same problem after two succesful weeks of wifi connection. The wifi function appears to have deteriorated with builds 653 and 656. My experience:
Under build 650 of the XO operating system, I had no problem connecting to a Meraki mesh wifi (open) after I whitelisted the XO. I use a DLink DIR655 router connected to a DSL feed. To the DLink is connected a Meraki mini broadcasting an open network and a secure network.
I upgraded to 653 - had trouble connecting - then went to build 656.
Now when the XO searches for a network, it "connects" to the phantom Network Mesh 1 (channel 1) of the non-existent school server. It also connects to my Meraki open mesh network but not properly.
The white ring appears, but no connection.
I can monitor all wifi traffic via the backend Meraki Dashboard: it shows the XO laptop as a user, and shows uploads of some 200kb but 0 kb downloads during the time of attempting to connect. i.e. no Internet connection achieved. I havn't found a way to shut down the phantom school nets which appear to be corrupting the connections. Signal strength from the nearest Meraki repeater can be 100% and still no connect.
I tried the solution of removing networks.org [
CORRECTION: networks.cfg ]
That just removes all colour from the connect icon in Home view.
The colour comes back after a few minutes, but still no Browse connect.
An hour later, I shut down my entire network (turned off DLink 655 router, Speedstream DSL modem and my Meraki minis). Then re-connected all. Lo and behold, the XO Laptop was able to reconnect to the Internet. This suggests that the solution is:
1. Remove networks.cfg
in Terminal mode (as others advise).
2. Turn off modem & router. Reconnect. Check you have Internet via other computer.
3. Connect via XO Laptop browser.
Good Luck. We all seem to need it.