some people are getting a null worldData bug. add a debug line to see if its here

src/main/java/baritone/cache/WorldProvider.java

@@ -83,6 +83,7 @@ public class WorldProvider implements IWorldProvider, Helper {
                     folderName = mc.getCurrentServer().ip;
                 } else {
                     //replaymod causes null currentServerData and false singleplayer.
+                    System.out.println("BARITONE: setting current world to null");
                     currentWorld = null;
                     return;
                 }