Thanks for chiming in this thread, Lawnman AMF.
The possible reasons why you're getting this error message are listed in the article provided by MorganB. If you've also cleared out the browser's cache and still getting the same issue, I recommend contacting our Customer Care Team. They can further check what's causing this behavior and might report it to our engineers.
Here are the steps:
- Click the Help icon located in the upper right-hand corner.
- In the Help window, click the Contact Us button located at the bottom.
- Enter your question and click Let's talk.
- Choose either Start a chat or Call us.
If you have the new QuickBooks Assistant help update, you can follow these steps:
- Go to the Help menu, and select Talk to a human.
- Choose Talk to a human again.
- Proceed with I still need a human.
- Click the Contact us link.
- Select either Start messaging or Get a call.
In the meantime, you can download the PDF copy of the invoice and email it outside of QuickBooks.
Here's how:
- On the left panel, click Sales > Invoices.
- Put a check mark on the invoices you want to send, and click the Batch Actions drop-down list.
- Select Print invoices. This will open a new window to print.
- In the Print page, click the Download icon located in the upper right-hand before the Print icon.
Please see this sample screenshot for a visual guide:

Please feel free to leave a comment on how it goes, or if you have other concerns. I'll be around to help you some more.