Hello,
Wrap your Activity inside a Workflow and use Invoke Workflow on Main, Then surround Main with a TryCatch.
Inside the Workflow you created, either do not surround it with a TryCatch or use Rethrow (not Throw because the Source would then be the Throw activity).
If your an exception occur in a Workflow itself invoked by another workflow (ex Main->Workflow1->Workflow2(ex), The sourrce of the exception would start to show you the Path the excecution took like under
`Invoke Workflow1 workflow: Activity Name
I havent found so far better way to refer to exact activity name using the exception object, of course you could hard-code on each worflow but i that would not a very scalable solution.
Hope it helps you.
You can also Refer to Badita post and example
Cheers