They may be a need to update your Adobe Reader to the latest version, mignonbonino.
- Open Adobe Reader in a separate window.
- Click Help.
- Select Adobe Reader.
- Go to the Adobe Reader Downloads page. The web page automatically detects your OS and Reader version.
- Choose Install Now.
- Open the downloaded file and follow the rest of the on-screen instructions to finish the updating process.
Once your PDF viewer is updated, set it up as a default application to open PDF documents.
You can check this article for more information: How to update, repair, or re-install Adobe Reader/Acrobat.
On the other hand, you can also check the setting in QuickBooks if there were changes made.
- Click the Gear icon.
- Select Account and settings.
- Click Sales on the left pane.
- Scroll down to select Online delivery edit, make sure to check the box for PDF Attached.
- Click Save, then Done to save changes.
Let me know if you have other questions about emailing invoices in QuickBooks Online