If you see this problem in the browser on PC first of all try to press CTRL+F5. that refreshes the system.
If this does not solve the problem then delete the cookies from your browser. Here is how to delete cookies from Chrome.
If you see this in the mobile app, you need to delete your app data. NOT the app!
Here is how to do that in Android, and here is how to do that in IOS. With this method, your business data will be fine, because all of your data is stored safely in the cloud.