Recently we got the below issue while saving the contact record. It was throwing this for one of our plugin steps registered on the update, for which we had already removed the profiling.
The profiling was already removed from the step.
It was the same error while trying to uninstall the profiler.
As mentioned in the error message we checked the Plug-in Profiler assembly in the Plugin Registration tool and could find the reference to the step there.
We unregistered the step there
This fixed the issue for us.
Hope it helps..