Nullpointerexception

					velocity = new Vector(0,0,0);
					Vector finalVector;
					Location newBlockLocation = null;
					Block skylineBlock;
					World playerWorld = player.getWorld();

					while (!(player.isSneaking())) {

						Location skylinePosition;
						Location skylinePositionM;
						playerLocation = player.getLocation();

						if (newBlockLocation == null) {
							newBlockLocation = blockLocation;
						} else {
							newBlockLocation = playerLocation.clone().add(0, 2, 0);
						}

						int vX = velocity.getBlockX();
						int vZ = velocity.getBlockZ();
						finalVector = null;

						if (vX == 0 && vZ == 0) {
							player.sendMessage(ChatColor.YELLOW + "Boucle 1");
							skylinePosition = newBlockLocation.clone().add(-1, -1, -1);
							skylinePositionM = newBlockLocation.clone().add(1,1,1);
							int xM = skylinePositionM.getBlockX();
							for (int x=skylinePosition.getBlockX();x<=xM;x++) {
								int yM = skylinePositionM.getBlockY();
								player.sendMessage(ChatColor.YELLOW + "for x = " + x);
								for (int y=skylinePosition.getBlockY();y<=yM;y++) {
									int zM = skylinePositionM.getBlockZ();
									player.sendMessage(ChatColor.YELLOW + "for y = " + y);
									for (int z=skylinePosition.getBlockZ();z<=zM;z++) {
										player.sendMessage(ChatColor.YELLOW + "for z = " + z);
										skylineBlock = playerWorld.getBlockAt(x,y,z);
										if (skylineBlock.getLocation() == newBlockLocation) {

										} else
										if (items.contains(skylineBlock.getType())) {
											listLocation.add(skylineBlock.getLocation()); //DOESN'T WORK SHIT. (nullpointerexception)
											if (listLocation.size() == 2) {
												Vector vec1 = ((listLocation.get(0)).clone().subtract(skylinePosition)).toVector();
												Vector vec2 = ((listLocation.get(1)).clone().subtract(skylinePosition)).toVector();

												if (vec1.angle(playerDir) <= Math.PI/2 || vec1.angle(playerDir) > -Math.PI/2) {
													finalVector = vec1;
												} else {
													finalVector = vec2;
												}
											}
										}
									}
								}
							}