SharePoint 2013 site is FBA and Windows authenticated. I have created one SharePoint 2013 workflow with an active directory user.

When I initiated the workflow with the windows authenticated user, the workflow was initiated and executed without any error. But when I did the same with a FBA user, the workflow was canceled and got an error i.e. 

> 
> **There has been an error authenticating the request**.
> 
> 
> 

The user profile was fully synchronized but when I searched for FBA users, they weren't there. But those FBA users which were created using **FBA User Management** were found in the user profile.

I also tried to initiate the workflow using a FBA user which was created via **FBA User Management** but again reach to that error.

Any assistance in this will be very grateful.