CodedUi Tests Not Recognizing Page Objects When Run on Local Machine

I am experiencing strange behavior in that all of a sudden all of my Coded UI tests are failing but only when run on my local machine giving System.NullReferenceException: System.NullReferenceException: Object reference not set to an instance of an object..

This occurs on the login page of our site and is referring to the username text entry. Strangely, if I open the UIMap for the page in Test Builder all of the objects are found including the username box so it’s only at runtime that this occurs.

In addition, these tests all run fine on our test rig as well as on other developer’s local machines. I’m stumped at the moment and wondered if anyone might have some ideas as to what the problem is here?

Can you please give the stack trace? we might be able to help you better.

Restarting VS and the workstation seems to have solved the issue.