The user who is running PPM (the application pool user) does not have permissions to read the doc store folder. Give this user full control to the entire doc store folder structure.
You may also get the following error in the Application Event Viewer. User Message: Fatal WebException occurred with status: ConnectFailure. Dev Message: Fatal web exception
Under Configuration | Environment Settings | Notification Settings, find the Notification Queue Name. Verify that this queue exists on the server. You will find the queue in Manage My Computer under Services and Applications \Message Queuing\Private Queues (or Outgoing Queue).
This may be an issue with the way users were imported / created in SBM. Perhaps, this is caused by an upgrade from an old version of TeamTrack. Check the TS_TIMEPREFERENCES column in the TS_USERS table in the Application Engine database for the user. The only valid values for TS_TIMEPREFERENCES are 0 or 1. If you have any other value in TS_TIMEPREFERENCES, replace it with a 0 or 1.