The first thing to do is to reload your page. If you leave a page with a customised test that has been started, don’t panic. Pix will remember it and you can pick up from where you left off. A loss of internet connection is the most common cause: refreshing your page will probably fix this.
If that doesn’t fix the error, you can firstly go to our website: there will be an information banner at the top of the page if there is a technical issue or maintenance operation on our side.
And if this is not the problem, you can contact us specifying the error you have encountered and providing a screenshot if possible, or any other information that will enable us to resolve the issue.