WebDriverWait Exception only thrown in Debug Mode in Visual Studio 2015
I believe this is a quirk of Visual Studio's debug mode. Essentially in debug mode exceptions are sometimes treated as a break even if it is appropriately handled within a try/catch.
Remember when you pass a func to Until() in WebDriver, that func is executed internally within a try. VS is likely hitting the (handled) exception in that method, which is why you do not see it during normal running.
See here for more info.
Here is a workaround, for example if you are trying to find an element:
wait.Until(driver => driver.FindElement( By.CssSelector(".cssClass")));You can do this:
wait.Until(driver => driver.FindElements( By.CssSelector(".cssClass")).FirstOrDefault());And it will work on both release and debug environments.