I try to preview my invoice but it says I am using an old template and cannot preview I have updated the app and done everything I can but still cannot preview my work

Thank you for reaching out to the QuickBooks Community, angelaayala0821-! Since that still happens, let's perform some troubleshooting steps to fix this. There are times when the browser is full of frequently accessed page resources, which causes errors or unusual responses. 

Let's start accessing your account using a different or private browser. You can use either of these shortcut keys:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Microsoft Edge: Ctrl + Shift + P
• Safari: Command + Shift + N

If it works, I recommend clearing your browser's cache. Doing so will remove the historical data and access QuickBooks with a clean slate.

Don't hesitate to reply anytime if you are still having issues. I'm more than happy to assist you. Take care, and have a great day ahead!