Well, I have a Windows 10 PC (ASUS Zenbook UX305CA w/ m3). I tried to open up my world to LAN to let someone else join. They have a Mac running OS X 10.11.6 (Mid 2011 Macbook Air w/ i5). Both have the same type of graphics card (Intel), but my computer has 4 more GB of RAM. Either way, whenever the other person tries to join, it says "io.netty.handler.timeout.readTimeoutexception". I can't seem to fix it, and I tried it on other worlds too, to no avail. My theory is that it is because of an incompatibility between Windows and Mac, but it might have worked before the Windows 10 Anniversary Update. Mojang please fix this.