@Burl Kerr, there should be no need to go to the LAN option, just keep it on the default network mode, I think it's online, make sure the world has multiplayer enabled. If that doesn't work then unfortunately you are running into one of the other issues. The Local Network option being turned off is just one of the issues people were running into. It looks like this issue has been tagged with a beta build so it looks like Mojang is working on it and hopefully we'll have fixes soon.
@Burl Kerr, there should be no need to go to the LAN option, just keep it on the default network mode, I think it's online, make sure the world has multiplayer enabled. If that doesn't work then unfortunately you are running into one of the other issues. The Local Network option being turned off is just one of the issues people were running into. It looks like this issue has been tagged with a beta build so it looks like Mojang is working on it and hopefully we'll have fixes soon.