Don't panic! Check that your internet connection is stable and empty your browser’s cache. Depending on your browser, methods may differ. Here's a link that will help: Refresh Your Cache.
If the problem persists, please contact us via the contact form in your app and give us as many details as possible about the issue: a screenshot, the action that triggers the problem, the error message, etc... All details are welcome, so please send us as much information as possible - we will fix the issue!