Comment 12 for bug 1533457

@Bernhard, it seems like you have stumbled into https://bugs.launchpad.net/neutron/+bug/1606844 which deals with the specific issue you've encountered.

However, the issue is triggered by some error in the server-side - please look at the neutron-server side for errors at roughly that time and provide traces/warnings/errors that appear there.

John.