I'm here to make sure your client can open the sent invoice, @slvrpony-hotmail.
You can either resent the impacted invoice or send a reminder to your client. Let me show you how:
By doing so, your client will be able to see the invoice. Make sure that there's an installed or updated Adobe on your client's unit to open the invoice.
I've also added these article that can guide you more about QuickBooks Self-Employed:
I'll be here if you have other QuickBooks Self-Employed concerns. Simply drop a comment to let me know. I'd be happy to lend a helping hand. Stay safe out there.