Hello cactusbookoeepin,

This error can occur if the process was interrupted by piled up cache files or sudden loss of internet connection.

Make sure you have a stable internet connection, then refresh (F5) the page.

If the same error occurs, we'll do browser troubleshooting steps. Cache files can boost QuickBooks processes, but it can also cause unexpected results. Thus, we encounter errors like this one. We can get rid of the cache-related issues by following these steps:

1. Let's use a private browser because it doesn't store cache files. Then, create an invoice again.
2. If you created the invoice successfully, we can clear the cache storage of your regular browser.
3. You can also use other supported browsers because each of it stores different cache files.

Let me know how this goes so I can help you more.