diff --git a/bukkit/src/main/resources/plugin.yml b/bukkit/src/main/resources/plugin.yml
index 588e46c4..e6b0ecdc 100644
--- a/bukkit/src/main/resources/plugin.yml
+++ b/bukkit/src/main/resources/plugin.yml
@@ -18,6 +18,8 @@ permissions:
         fawe.plotsquared.trusted: true
   fawe.plotme:
     default: true
+  fawe.bypass.regions:
+    default: false
   fawe.bypass:
     default: false
     children:
diff --git a/core/src/main/java/com/boydti/fawe/util/ExtentTraverser.java b/core/src/main/java/com/boydti/fawe/util/ExtentTraverser.java
index 4b40f25e..64a0a6e3 100644
--- a/core/src/main/java/com/boydti/fawe/util/ExtentTraverser.java
+++ b/core/src/main/java/com/boydti/fawe/util/ExtentTraverser.java
@@ -60,7 +60,7 @@ public class ExtentTraverser<T extends Extent> {
     }
 
     public <U> U findAndGet(Class<U> clazz) {
-        ExtentTraverser<Extent> traverser = find(clazz);
+        ExtentTraverser<Extent> traverser = find((Class) clazz);
         return (traverser != null) ? (U) traverser.get() : null;
     }
 
@@ -68,7 +68,7 @@ public class ExtentTraverser<T extends Extent> {
         try {
             ExtentTraverser<T> value = this;
             while (value != null) {
-                if (clazz.isInstance(value.root)) {
+                if (clazz.isAssignableFrom(value.root.getClass())) {
                     return (ExtentTraverser<U>) value;
                 }
                 value = value.next();
diff --git a/core/src/main/java/com/boydti/fawe/util/WEManager.java b/core/src/main/java/com/boydti/fawe/util/WEManager.java
index c18ca413..7a54591f 100644
--- a/core/src/main/java/com/boydti/fawe/util/WEManager.java
+++ b/core/src/main/java/com/boydti/fawe/util/WEManager.java
@@ -15,9 +15,8 @@ import com.sk89q.worldedit.extent.AbstractDelegateExtent;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.regions.Region;
 import java.lang.reflect.Field;
-import java.util.ArrayDeque;
-import java.util.HashSet;
-import java.util.Set;
+import java.util.*;
+import java.util.stream.Collectors;
 
 public class WEManager {
 
@@ -98,33 +97,37 @@ public class WEManager {
         }
         player.setMeta("lastMaskWorld", world);
         Set<FaweMask> masks = player.getMeta("lastMask");
-        HashSet<Region> regions = new HashSet<>();
+        Set<Region> backupRegions = new HashSet<>();
+        Set<Region> regions = new HashSet<>();
+
+
         if (masks == null) {
             masks = new HashSet<>();
         } else {
-            boolean removed = false;
-            if (masks.isEmpty()) {
-                removed = true;
-            } else {
-                for (FaweMask mask : masks) {
-                    Region region = mask.getRegion();
-                    if (!region.contains(loc.x, loc.y, loc.z)) {
-                        removed = true;
+            synchronized (masks) {
+                boolean removed = false;
+                if (!masks.isEmpty()) {
+                    Iterator<FaweMask> iter = masks.iterator();
+                    while (iter.hasNext()) {
+                        FaweMask mask = iter.next();
+                        if (mask.isValid(player, type)) {
+                            Region region = mask.getRegion();
+                            if (region.contains(loc.x, loc.y, loc.z)) {
+                                regions.add(region);
+                            } else {
+                                removed = true;
+                                backupRegions.add(region);
+                            }
+                        } else {
+                            removed = true;
+                            iter.remove();
+                        }
                     }
-                    if (!mask.isValid(player, type)) {
-                        removed = true;
-                        break;
-                    }
-                    regions.add(region);
                 }
-            }
-            if (removed) {
-                masks.clear();
-                regions.clear();
-            } else {
-                return regions.toArray(new Region[regions.size()]);
+                if (!removed) return regions.toArray(new Region[regions.size()]);
             }
         }
+        Set<FaweMask> tmpMasks = new HashSet<>();
         for (final FaweMaskManager manager : managers) {
             if (player.hasPermission("fawe." + manager.getKey())) {
                 try {
@@ -138,6 +141,12 @@ public class WEManager {
                 }
             }
         }
+        if (!tmpMasks.isEmpty()) {
+            masks = tmpMasks;
+            regions = masks.stream().map(mask -> mask.getRegion()).collect(Collectors.toSet());
+        } else {
+            regions.addAll(backupRegions);
+        }
         if (!masks.isEmpty()) {
             player.setMeta("lastMask", masks);
         } else {
diff --git a/nukkit/src/main/resources/plugin.yml b/nukkit/src/main/resources/plugin.yml
index 46c76f43..a8b38f9b 100644
--- a/nukkit/src/main/resources/plugin.yml
+++ b/nukkit/src/main/resources/plugin.yml
@@ -10,6 +10,8 @@ permissions:
         fawe.plotsquared.trusted: true
   fawe.plotme:
     default: true
+  fawe.bypass.regions:
+    default: false
   fawe.bypass:
     default: false
     children: