Hi
Pre transition events are associated with life cycle of an item type and voting are associated with Workflow of an item type.
1. Check whether the method is triggered before the workflow sign off activity.
2. Check whether the life cycle transition is happening before sign off or after sign off.
I suspect, there is a Promotion attached to an activity in workflow and the method is triggering during that promotion.
Example:
Life Cycle : Start --> In Progress --> Closed
Workflow : New --> In Review --> Closed
Assume
Added Pre Transition event in Start state in life cycle
Added Promotion in In Review activity (Life cycle state change from Start --> In Progress)
On Sign Off from New to In Review,
First sign off will happen, then on complete of this sign off activity, will trigger the life cycle promotion from Start to In Progress
So, Pre Transition method is added on start of this promotion so it will throw error.
Let me know if it helps.
Thanks
Gopikrishnan R