Ok - Need to determine if it's the system in general or that wf template.
1. Create a new very simple WF template (e.g one Activity, to Creator) and Initiate from the WF admin UI. Does that execute ok?
2. If the test wf process works, initiate the problem wf template the same way, not associated to any object.
3. If that initiates ok, iniitiate again from the wf admin UI, associated with a new Change Request or whatever it is normally used with.
Curious what you find. 