Clarity 2020.1 task server update 20.1.7.0 not working

This is what appears on the Clarity Task Log Dialog.

Checking...10:26:41 AM
Evaluating 51 tasks...
Evaluating Task: Task: 140136: TaskSequence: New
Plugin Options:
Same mutex is needed, just reuse: {96188ffc-0348-49a2-94c6-8d854786f502}PDFREGISTRYCLARITYPDF
An exception while idling was encountered: ArgumentNullException: Value cannot be null.
Parameter name: source Stack: at System.Linq.Enumerable.Select[TSource,TResult](IEnumerable`1 source, Func`2 selector)
at Clarity.IProjectMonitor.ProjectFileAccessManager.GetProjectAccessorsAsString()
at CohortRevitTaskServer.Controller.Process()
Too many consecutive exceptions... pausing callbacks...

the issues is the lasted update 20.1.7.0  dropped an extra DLL in place for non-ProjectWise customers.

The fix is to search and delete Clarity.ProjectWiseFileAccessor.dll in your Task Server folders for each version.  example C:\Program Files\IMAGINiT Technologies\Clarity Task Server for Revit\2017   , 2018,  2019 , 2020.