Why running a selected single coded step fails?
Problem
When a single coded step is selected and run it fails with the following exception:
System.ArgumentNullException: Start reference element can't be null. Please make sure the DOM is loaded by either calling NavigateTo() to a page or add browser RefreshDomTree() prior to the code which needs the DOM.
Cause
This happens because a single coded step is not set to automatically call refresh of the DOM but at the same time it needs any DOM tree to execute against.
Solution
Add a statement to refresh the DOM tree as first row in the coded step.
// Use Manager.ActiveBrowser for a web application
Manager.ActiveBrowser.RefreshDomTree();
// Use Manager.ActiveApplication for a wpf application
Manager.ActiveApplication.MainWindow.RefreshVisualTrees();