Profile Workflow no steps in Plugin Registration Tool

Hi

We have CRM 2013 on premise (rollup 3 on SP1)

I'm new to CRM and am I'm hitting issues trying to step through the code of a custom workflow activity.

The issue is when attempting to profile the workflow.

In the profiler settings dialog, selecting the workflow from the drop down doesn't show up any steps. In fact selecting any workflow doesn't show steps so something is a miss here.

I've logged in using an admin account, running the tool as admin also.

I've tried plugin reg tool from 2011 and 2015 sdk also with same issue.

Any ideas would be appreciated

Thanks

Liam