Torbutton's New Identity fails under high load

It seems there are cases where our New Identity fails under high load. In this case users are getting the following error:

Torbutton cannot safely give you a new identity. It does not have access to the Tor Control Port.

Are you running Tor Browser Bundle?

This got reported on our blog: https://blog.torproject.org/blog/tor-browser-65a5-released#comment-223933.