When you try to send a PDF as an attachment using Acrobat DC on macOS Mojave, you see the following error message: “An error occurred while trying to create a mail document”.

On macOS Mojave, when you first install Acrobat DC, you get a prompt to provide permissions to Acrobat and default mail client (mail or Outlook). If you deny the permissions that time, you see this error message while sending PDFs as attachments.