If you have a 2008/R2 failover cluster then it’s possible you may come across the following errors at some point after an unplanned failover:
Unable to obtain the primary cluster name identity token
An attempt has been made to operate on an impersonation token by a thread that is not currently impersonating a client
As a result, your clustered resources may refuse to start.
Now, assuming that you haven’t done something stupid, like deleting the cluster computer account from AD, you should be able to resolve this problem by right-clicking on the failed CNO on the Summary page of the Failover Cluster Manager, go to “More Options” and then “Repair Active Directory Object”. You should then be able to start all the cluster resources successfully. Thanks to wonhchoi.com for pointing me in the right direction.
As to what might have caused this problem in the first place? Well that’s still something of a mystery to me at the moment…