I was given two pages with C# code and the interviewer told me it did not compile. Find the issue and fix it. There issue was that there was an abstract class but not derived class. Another issue was that in a console.write statement, the two labels were reversed, so that they reported the wrong values. A third (minor) issue was that conole.write statements output, although technically correct, were not human readable (no spaces or punctuation).
Then I was asked how to test a dialog window that had a text field with a browse button and the standard 2 buttons (OK, Cancel)