I think Nest is having the issue today. That error message is on their page, not Vera's. I'm in no way defending the WWN plugin, but it is much better than it has been in the past.
EDIT: I went into my Nest account and removed MiOS from my Works with Nest list. I then authorized Vera again and everything started up normally. All my Nest devices are seen again. (Hopefully it will last a while.)
EDITED EDIT: The WWN plugin took a dive again. But so did one of my ZigBee lights, again. Ended up deleting the light and authorizing again. Now I need to replace the ZigBee with something else. Lost the config on this same light twice and I need it to be more reliable.