Failure while creating a bridge device using virt-manager GUI.

Issue

• Received below error while trying to configure a Bridge Network interface for virt-manager.

Error creating interface: 'Could not define interface: internal error could not get interface XML description: unspecified error - errors in loading some config files'

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 44, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/createinterface.py", line 1146, in do_install
    self.interface.install(meter, create=activate)
  File "/usr/lib/python2.6/site-packages/virtinst/Interface.py", line 242, in install
    raise RuntimeError(_("Could not define interface: %s" % str(e)))
RuntimeError: Could not define interface: internal error could not get interface XML description: unspecified error - errors in loading some config files