Yes, it works fine in 15.71, but in 15.72 and 15.73 it fails. If I downgrade back to 15.71 the test works fine again.
It is hard to describe I guess, but you see the If Object line in the screenshot? It is looking to see if an item exists on the screen. In this case it does not.
When that If returns false, the very next step following the If statement will throw a name mapping failure message.
The name mapping itself is fine. If I disable that If statement, the test will complete fine. If I move the item that failed above the If statement, it will complete that step, but will now fail on the next step that is following the If statement.
If I put a debugging pause on the step immediately following the If, then when the test pauses I right click on that step and choose "Highlight on screen" it will highlight and when I hit continue the test will complete fine. If I pause, but do not highlight the item, when I hit continue, the test will still fail like it does without the debugging pause.
Hope that helps you understand what is happening.