It seems that this error is related to a sync issue between your browser session and the QuickBooks servers. This interruption in data prevents the invoice from recognizing your manual cash payment.
To resolve this, I recommend signing out of your account and refreshing your browser before signing back in. This process refreshes your connection to the QuickBooks servers and clears the error. If issues persist, switch to a different browser to rule out browser-related issues.
Feel free to return if you have follow-up questions.
