fix #550

worldedit-core/src/main/java/com/boydti/fawe/wrappers/AsyncPlayer.java

@@ -143,10 +143,11 @@ public class AsyncPlayer extends PlayerProxy {
 
     @Override
     public void floatAt(int x, int y, int z, boolean alwaysGlass) {
+        if (alwaysGlass || !isAllowedToFly()) {
             RuntimeException caught = null;
             try {
-            EditSession edit = new EditSessionBuilder(WorldWrapper.unwrap(getWorld()))
-                .player(unwrap(getBasePlayer())).build();
+                EditSession edit =
+                    new EditSessionBuilder(WorldWrapper.unwrap(getWorld())).player(unwrap(getBasePlayer())).build();
                 edit.setBlock(BlockVector3.at(x, y - 1, z), BlockTypes.GLASS);
                 edit.flushQueue();
                 LocalSession session = Fawe.get().getWorldEdit().getSessionManager().get(this);
@@ -156,10 +157,13 @@ public class AsyncPlayer extends PlayerProxy {
             } catch (RuntimeException e) {
                 caught = e;
             }
-        setPosition(Vector3.at(x + 0.5, y, z + 0.5));
             if (caught != null) {
                 throw caught;
             }
+        } else {
+            setFlying(true);
+        }
+        trySetPosition(Vector3.at(x + 0.5, y, z + 0.5));
     }
 
     @Override