Fixes #943

bukkit/src/main/java/com/boydti/fawe/bukkit/v0/BukkitQueue_0.java

@@ -95,6 +95,18 @@ public abstract class BukkitQueue_0<CHUNK, CHUNKSECTIONS, SECTION> extends NMSMa
         return super.supports(capability);
     }
 
+    @Override
+    public void sendChunk(FaweChunk fc) {
+        if (!Fawe.isMainThread()) {
+            startSet(true);
+            try {
+                super.sendChunk(fc);
+            } finally {
+                endSet(true);
+            }
+        }
+    }
+
     @Override
     public void sendChunkUpdate(FaweChunk chunk, FawePlayer... players) {
         if (supports(Capability.CHUNK_PACKETS)) {