I've seen a lot of other mods do it but I can't get mine to be clickable (in the sense that it asks to open it in your browser when you click on it). What am I doing wrong?

 

public class LoadingEvent
{
private static String url = "http://missapocalypse.wix.com/fandomcraft";

@SubscribeEvent
public void playerLogsIn(PlayerLoggedInEvent event)
{
	try
	{
		URL site = new URL(url);

		event.player.addChatMessage(new ChatComponentText("You are playing '" +
				EnumChatFormatting.RED + "FandomCraft v4S" + EnumChatFormatting.WHITE +
				",' singleplayer version of the '" + EnumChatFormatting.GREEN +
				"Fable Update" + EnumChatFormatting.WHITE + ".'"));

		event.player.addChatMessage(new ChatComponentText("You can check for updates at "  +
				EnumChatFormatting.GOLD + site));
	}
    catch (MalformedURLException e)
    {
      e.printStackTrace();
    }

}
}

Take a look at the ClickEvent.class as it contains a open url action that will allow you to open your url upon clicking the text.

Take a look at what I have in my mod:

 

https://github.com/Zalth-One-Three/Zombie-Infection/blob/master/src/main/resources/assets/zombieinfection/lang/en_US.lang#L9

https://github.com/Zalth-One-Three/Zombie-Infection/blob/master/src/main/java/com/zalthonethree/zombieinfection/updatechecker/UpdateChecker.java#L111-112