I called QB support and spent a couple of hours with them. I believe engineering is working on this problem and the change is due to the new look invoice upgrade. Work around for now is to click the button to use the old invoice style (at the top). Then at the bottom of the invoice click the button to include the attachments. Then change the style back to the new invoice and the attachment will get sent. I only have a few of my invoices that need attachments included so not a big deal for me. Hope this helps! Let me know if you need more instructions to do this and I will walk through it to see exactly what the buttons say.