Please check if the problem might be caused by your internet connection.
In case you are using the app you can try to deinstall it and download it again. Moreover, you can try to delete the cache in the app settings.
If you are using a Computer/Laptop, it could be possible that the problem is caused by your browser. Please update your browser and delete the cookies. You could also try using a different browser - we recommend using Google Chrome.
If you have any further questions feel free to contact my support.