Better constructor error handling in QueueProvider.

Add back default constructor requiring world to QueueCoordinator to indicate extents require this constructor

Core/src/main/java/com/plotsquared/core/queue/BasicQueueCoordinator.java

@@ -69,6 +69,7 @@ public abstract class BasicQueueCoordinator extends QueueCoordinator {
     private Runnable whenDone;
 
     public BasicQueueCoordinator(@Nonnull World world) {
+        super(world);
         this.world = world;
         this.modified = System.currentTimeMillis();
     }

Core/src/main/java/com/plotsquared/core/queue/DelegateQueueCoordinator.java

@@ -50,6 +50,7 @@ public class DelegateQueueCoordinator extends QueueCoordinator {
     private final QueueCoordinator parent;
 
     public DelegateQueueCoordinator(QueueCoordinator parent) {
+        super(parent == null ? null : parent.getWorld());
         this.parent = parent;
 
         if (parent != null) {

Core/src/main/java/com/plotsquared/core/queue/QueueCoordinator.java

@@ -52,7 +52,10 @@ public abstract class QueueCoordinator {
 
     @Inject private GlobalBlockQueue blockQueue;
 
-    public QueueCoordinator() {
+    /**
+     * Default constructor requires world to indicate any extents given to {@link QueueCoordinator} also need this constructor.
+     */
+    public QueueCoordinator(@Nullable World world) {
         PlotSquared.platform().getInjector().injectMembers(this);
     }
 

Core/src/main/java/com/plotsquared/core/queue/QueueProvider.java

@@ -25,11 +25,17 @@
  */
 package com.plotsquared.core.queue;
 
+import com.plotsquared.core.PlotSquared;
 import com.sk89q.worldedit.world.World;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import javax.annotation.Nonnull;
 
 public abstract class QueueProvider {
+
+    private static final Logger logger = LoggerFactory.getLogger("P2/" + PlotSquared.class.getSimpleName());
+
     public static QueueProvider of(@Nonnull final Class<? extends QueueCoordinator> primary) {
         return new QueueProvider() {
 
@@ -37,6 +43,11 @@ public abstract class QueueProvider {
                 try {
                     return (QueueCoordinator) primary.getConstructors()[0].newInstance(world);
                 } catch (Throwable e) {
+                    logger.info("Error creating Queue: " + primary.getName() + " - Does it have the correct constructor(s)?");
+                    if (!primary.getName().contains("com.plotsquared")) {
+                        logger.info("It looks like " + primary.getSimpleName()
+                            + " is a custom queue. Please look for a plugin in its classpath and report to themm");
+                    }
                     e.printStackTrace();
                 }
                 return null;