Whenever I start my game and go onto the Multiplayer server list, the servers all say "Can't connect to server" but when I refresh the page, it says the normal servers MOTD in the listing.
Code analysis (MCP names), comments, and additional note by Kyle Repinski
I've analyzed the issue and found it's a race condition with the multi-threaded server pinger code. The server pinging code (net.minecraft.client.network.ServerPinger) is run in multiple threads, and each thread calls net.minecraft.network.NetworkManager.createNetworkManagerAndConnect(). This function uses "lazy loaders" (net.minecraft.util.LazyLoadBase) to initialize some static variables. The issue lies in net.minecraft.util.LazyLoadBase.getValue(). This function is not thread-safe. Below you'll find the code in question with comments explaining exactly what is happening and how to fix it.
Note that depending on the speed of the computer, this bug might not occur. If the first thread finishes quickly enough everything will appear normal.