An application error has occurred while processing your request

Thanks for posting in the Community, Sergio. Let me provide you with the appropriate steps you may take to narrow down the cause of the error received when trying to send an invoice. 

As you have received a specific error, I'd recommend performing a browser troubleshooting on your end. This way, we'll identify why you've received this error while sending an invoice. 

You may use either of these shortcut keys:

• Mozilla Firefox: press Ctrl + Shift + P
• Internet Explorer: press Ctrl + Shift + P
• Safari: press Command + Shift +N

If it works fine from there, switch back to your regular browser and clear its cache. On the other hand, if the issue persists, try using other supported browsers to narrow down the cause. 

Additionally, you'll want to check this article and learn how to personalize and add specific info to your sales forms in QuickBooks Online: Customize invoices, estimates, and sales receipts in QuickBooks Online.

I'm always here to assist if you need additional assistance managing your invoices and any QuickBooks-related queries. Keep safe. 

This is happening for me today 2/23/26. It occurs on all browsers. It just started happening today. I also tried in incognito mode. It happens when I enter a product/service, any of them into the field. The error comes up: 
"An application error has occurred while processing your request"

also cleared cache several times and issues persists. Is there a software issue tonight?

Lastly, i tried on multiple computers and get same error message when creating an invoice.

Hi, Nezi. The error you're experiencing occurs when the system encounters unexpected issues while processing your request. This is often due to cached data or browser-related problems that can interfere with QuickBooks Online’s (QBO) functionality.

I appreciate that you took the time to clear your browser's cache, use an incognito window, and test on multiple devices as part of your initial troubleshooting.

Since the issue persists, I recommend contacting our QBO Live Support team directly. They can review the error on your account and ensure that you’re able to create invoices and manage your tasks again.

1. Go to the Help icon, then select the Assistance tab.
2. In the box provided, briefly describe your issue or type Contact Support.
3. Choose either Chat or Callback for help.

To ensure timely assistance, please check our support hours.

Please let me know if there's anything else I can help you with. I'll respond to you promptly.

Woke up this morning and it is working now for some reason. 

Hi there, @nezi. Thank you for sharing an update regarding managing your Invoices. Please know that we're continuously working to ensure a seamless experience in managing your Invoices in QuickBooks Online(QBO). 

As always, feel free to visit our Community Forum for any additional questions or concerns. And we are here to help!