Hi there, Sally38.
Welcome aboard to the QuickBooks Community. It would be my pleasure to answer any questions you may have about sending invoices from QuickBooks Self-Employed.
I've checked here, and we haven't received any reports from other users concerning the issue with emailing within QuickBooks Online. When you say the invoice will not load when viewed, are you referring to the emailed invoice? Or when opening it within QuickBooks?
For now, we can perform some basic troubleshooting to determine if the problem is system related. You can start with using private or incognito mode.
If this works, you can shift back to the regular browser and clear its cache. You also have the option to try switching to a different browser.
Please let me know if you need further assistance concerning the invoices. I'll keep an eye out on your response.