Access to the path is denied

I just upgraded my local machine from Neuron 3.1.0.275 to 3.5.2 and now I get a System.UnauthorizedAccessException "Access to the path is denied"

The stack trace is as follows:

   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.Threading.EventWaitHandle.OpenExistingWorker(String name, EventWaitHandleRights rights, EventWaitHandle& result)
   at System.Threading.EventWaitHandle.OpenExisting(String name, EventWaitHandleRights rights)
   at Neuron.Esb.Channels.ESBChannelManager..ctor(ESBTopicContext topicContext, String channelType)
   at Neuron.Esb.Channels.ESBTopicContext.CreateChannel()
   at Neuron.Esb.Party.PreConnect()
   at Neuron.Esb.Party.Connect()
   at ESBPublisher.<SendMessage>d__0.MoveNext() in ...

I have made no other changes. We upgraded a development testing server as well and receive the same error.

Thoughts?