--- old/modules/graphics/src/main/native-glass/mac/GlassWindow+Overrides.m	2015-04-06 16:54:46.000000000 -0400
+++ new/modules/graphics/src/main/native-glass/mac/GlassWindow+Overrides.m	2015-04-06 16:54:46.000000000 -0400
@@ -114,8 +114,11 @@
     }
     
     // Call the notification method
-    GET_MAIN_JENV;
-    (*env)->CallVoidMethod(env, self->jWindow, jWindowNotifyDestroy);
+    assert(pthread_main_np() == 1);
+    JNIEnv *env = jEnv;
+    if (env != NULL) {
+        (*env)->CallVoidMethod(env, self->jWindow, jWindowNotifyDestroy);
+    }
 }
 
 - (void)windowWillMove:(NSNotification *)notification