Script Error: Employees: Write permission denied for value "Disabled permanently".

I have this script which throws "Employees: Write permission denied for value "Disabled permanently"." error during execution. What I'm missing?

Public Function CCC_InActivatePerson(
    ByVal UID_Person As String) As String
	
	Dim Person As ISingleDbObject = Connection.CreateSingle("Person", UID_Person)
	Person.PutValue("IsInActive", 1)
	Person.PutValue("XMarkedForDeletion", 0)
	Person.Save()
	
	Return String.Empty

End Function