I am trying to setup a new Workflow manager & Service Bus Farm in my local machine. and in the stage of Create a new service bus farm getting error as "Unable to cast object of type 'System.DirectoryServices.AccountManagement.GroupPrincipal' to type 'System.DirectoryServices.AccountManagement.UserPrincipal'" .
Please suggest any resolution.
Specification :- SQL Server 2012 Enterprise edition, Workflow manager 1.0 refresh(CU2)+CU5, Service Bus 1.1 CU1, Windows fabric 1.0.970.0

You need to mark sure to run the Workflow Manager with a domain account.
A blog ("Farm Creation" section) lists this similar issue for your reference: Fun With Installing Service Bus for Windows
Also there is a TechNet blog which lists tips for Successful Installation of Workflow Manager, you can have a look at it.