This error note is coming up when trying to save an estimate - An application error has occurred while processing your request

I've got troubleshooting steps to fix the error message you encountered.

QuickBooks Online may experience loading errors if you have too many tabs open or if your browser is full of old data. To address this, let's close any extra QuickBooks tabs or windows. You can also refresh your current page by pressing F5 on your keyboard or clicking the Refresh button in your browser to start a new session.

If the issue persists after trying the steps above, let's access your QuickBooks Online in a private or incognito browser window. This helps the site run better by ignoring saved files and extra add-ons. You can also try using a different browser, like Google Chrome, for better performance.

After completing these steps, let's attempt to save your estimate again to see if that fixes the problem. 

If you have further concerns, please feel free to ask. We're here to help.