我是 Ubuntu 的新手，我有点困惑。我想为我的一个虚拟机创建一个虚拟网络，所以我打开了 virt-manager 并去编辑 -> 连接详细信息并停止默认并创建一个新的虚拟网络。现在我的虚拟机无法启动，我收到此错误消息。
"Error starting domain: Requested operation is not valid: network 'default' is not active"
Traceback (most recent call last):
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 89, in cb_wrapper
callback(asyncjob, *args, **kwargs)
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 125, in tmpcb
callback(*args, **kwargs)
File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 82, in newfn
ret = fn(self, *args, **kwargs)
File "/usr/share/virt-manager/virtManager/domain.py", line 1508, in startup
self._backend.create()
File "/usr/lib/python2.7/dist-packages/libvirt.py", line 1062, in create
if ret == -1: raise libvirtError ('virDomainCreate() failed', dom=self)
libvirtError: Requested operation is not valid: network 'default' is not active
有谁知道为什么我不能为这个 vm 创建一个虚拟网络并禁用/删除默认值？