virtual box中的ubuntu处于休眠状态，启动报错：
不能为虚拟电脑 big_ubuntu_1204 打开一个新任务. The VM session was closed before any attempt to power it on.
返回错误代码：E_FAIL (0x80004005)
其实右键ubuntu，点击清除保存的状态就可以了。
