Summery:
A group of my friends and myself have encountered issues with running LAN worlds on any version of Minecraft following 1.8.9. where the LAN world is not showing up under the multiplayer tab.

What I expect to happen:
The hosting computer will start the LAN game via the "Open to LAN" tab under the options screen within game. In previous versions of Minecraft, the LAN game will appear under the Multiplayer Tab from the main menu, allowing multiplayer games over a Local Area Network.

What actually happens:
Upon the host computer opening a LAN world, the multiplay LAN world will not appear in any list of available games under the Multiplayer Tab when the second person goes to join the LAN world.

We are running on Macintosh Laptops running El Capitan as our OS.
We are on the same wireless internet connection, using a Local Area Network.
We have checked our firewalls to ensure neither the JAVA Plug-In nor Minecraft is blocked from internet connections.
We have attempted to play LAN together at several different locations to ensure this was not a Wireless connection error.

Minecraft runs fine in single player worlds, and on a realm server a friend purchased.
We have all recently re-installed Minecraft and have seen no change in the issue.
We have attempted the Direct Connect option for joining LAN Games and encounter the same issue.

I reported this issue to the Mojang help/support site, and was directed to report it as a bug, given their site did not the team/staff for technical support/ help.
I have also looked through the support forums for help with this issue and all the articles i have seen replying advise checking the internet connection, ensuring players are using the same version, checking the firewall and reinstall the game, all of which have been done.

If you have a technical support team or page I can contact, please advise or reply with any information pertaining to this issue.

Reily M.