Intro course project - Assign Error

I created the first project from the Intro course in Studio but it errors when running. Here are the details:

19.5.0+Branch.master.Sha.a03bc4726ca82b7bb3addb0d04106dc150b31fba

Source: Assign

Message: Object reference not set to an instance of an object.

Exception Type: System.NullReferenceException

An ExceptionDetail, likely created by IncludeExceptionDetailInFaults=true, whose value is:
System.NullReferenceException: Object reference not set to an instance of an object.
at lambda_method(Closure , ActivityContext )
at Microsoft.VisualBasic.Activities.VisualBasicValue1.Execute(CodeActivityContext context) at System.Activities.CodeActivity1.InternalExecuteInResolutionContext(CodeActivityContext context)
at System.Activities.Runtime.ActivityExecutor.ExecuteInResolutionContext[T](ActivityInstance parentInstance, Activity1 expressionActivity) at System.Activities.InArgument1.TryPopulateValue(LocationEnvironment targetEnvironment, ActivityInstance activityInstance, ActivityExecutor executor)
at System.Activities.RuntimeArgument.TryPopulateValue(LocationEnvironment targetEnvironment, ActivityInstance targetActivityInstance, ActivityExecutor executor, Object argumentValueOverride, Location resultLocation, Boolean skipFastPath)
at System.Activities.ActivityInstance.InternalTryPopulateArgumentValueOrScheduleExpression(RuntimeArgument argument, Int32 nextArgumentIndex, ActivityExecutor executor, IDictionary2 argumentValueOverrides, Location resultLocation, Boolean isDynamicUpdate) at System.Activities.ActivityInstance.ResolveArguments(ActivityExecutor executor, IDictionary2 argumentValueOverrides, Location resultLocation, Int32 startIndex)
at System.Activities.Runtime.ActivityExecutor.ExecuteActivityWorkItem.ExecuteBody(ActivityExecutor executor, BookmarkManager bookmarkManager, Location resultLocation)

What happen if PN string is empty? First check if robot is finding some text in OCR activity

Hi buddy @sciccone

Welcome to UiPath community buddy

This error usually occurs when the object we use ( here PN ) has no reference to the place from where it gets the value…
So check once the PN has any value…that means check once whether the get OCR is fetching any value…for make the page visible and open in foreground of the screen, the moment when bot starts executing…so that you will get the value on ocr scrapping…
Thats all buddy you are done
Cheers…
@sciccone