I'm here to share how your clients can review your invoices without the error, @krafty_kutz-outl.
Your client's browsing history and cache can be the reason why they're having issues opening your invoices for them. You can let them perform a few browser troubleshooting steps so they can easily access it.
First off, let them view your invoice using a private or incognito window of their browser. Share these key shortcuts with them so they can easily open them with their browser:
If it works without issues, let them clear their regular browser’s cache to delete all the history and make their browser function efficiently. If they receive the same error message, consider letting them access your invoice using other browsers.
Finally, I've got you this helpful article for a better view of how you can continue invoicing and work well with your business in QuickBooks: QuickBooks Self-Employed Overview.
You can always leave a comment below if you have any other concerns aside from QuickBooks invoicing. I've got your back. Stay safe!
We have an active investigation on invoice showing as "Invoice unavailable" when trying to view on it. I'd recommend to contact our Support team to have your account added on the affected list and for you to receive a real time update.
Let me know if you have any other questions.