Your customer made a payment more than the invoice balance, which created a credit. How to apply a credit from an overpayment.
Your QBO needs a little refresh so it'll recognize that there's no overpayment, chopellhamu.
Before you receive the payment, kindly click the Reload icon beside the QBO URL. Another way to do this is by pressing CTRL+F5 on your keyboard. Then, restart your browser to completely refresh the program.
If you get the same message, let's proceed with opening QBO using an Incognito window. This will help us check if the behavior is cache related. If you don't get the message there, go back to your old browser and clear the cache.
If you have questions, you can always leave a reply.