@ashish fugat my guess is that it's the difference between Functions 1.x which works with .NETFX and >2.x which works with .NETCORE, see here. For ServiceBus trigger, it's stated that 1.x should use BrokeredMessage where
LockToken is of type Guid. For 2.x and later, Message should be used instead. However, I could not find LockToken property on that type. I would suggest posting a new issue on the azure webjobs sdk repo to see why the LockToken property was switched from Guid to string.