Unity编辑器经常提示一个Warning：
Uncaught exception in async net callback: Object reference not set to an instance of an object
UnityEditor.AsyncHTTPClient:Done(State, Int32)
Unity的令人费解的BUG，解决方法为取消Show Asset Store search hits选项：
UnityEditor.AsyncHTTPClient:Done(State, Int32)异常处理
原文：http://568464209.blog.51cto.com/7726521/1769605