Hi MatthieuBisous,
Have you made any changes to the domain recently? If so, your old domain may no longer be accessible, leading to 404 errors for the print invoice order links in the admin emails.
If no changes have been made to the domain, please follow the steps below to identify any conflicting plugins/themes. This will help the root cause of the issue.
1. Deactivate all the plugins except WooCommerce and the print invoice plugin. After that, check if the issue is fixed.
2. If the issue doesn’t persist in this minimum setup, then kindly start activating the plugins one by one and check for the conflicting plugins.
3. If the issue still doesn’t occur, then it is possible that there is some conflict with the currently activated theme. Kindly change the theme to the default WordPress theme and check for the issue.
Please let me know the result. If the above does not help, please create the ticket here on our support tool so that we can communicate in detail.
Regards,
Nikhil.