I have a document review workflow that, at one stage, copies the document over to another library. Recently, I started having a problem where, when it gets to the copy document action, the workflow goes to suspended and will not move on. The document is not copied.
This is the error that is showing up next to the 'Suspended' workflow status:
Details: An unhandled exception occurred during the execution of the workflow instance. Exception details: System.ArgumentNullException: Value cannot be null. Parameter name: Input at Microsoft.Activities.Hosting.Runtime.Subroutine.SubroutineChild.Execute(CodeActivityContext context) at System.Activities.CodeActivity.InternalExecute(ActivityInstance instance, ActivityExecutor executor, BookmarkManager bookmarkManager) at System.Activities.Runtime.ActivityExecutor.ExecuteActivityWorkItem.ExecuteBody(ActivityExecutor executor, BookmarkManager bookmarkManager, Location resultLocation)