Sometimes a test fails because next exception is thrown:

org.openqa.selenium.UnhandledAlertException: Unexpected modal dialog (text: This page is asking you to confirm that you want to leave - data you have entered may not be saved.): This page is asking you to confirm that you want to leave - data you have entered may not be saved.

It seems that depending on previous execution, the browser contains some old values and when the new test tries to create a new item, since browser is in a form with some data, the modal dialg is shown.

To avoid this situation, pushing confirm button might be a good solution to avoid this problem instead of making test fails.