e-Newsletter error when sending

When I attempt to send a test email I get this error:

"Failed to generate email body."

When I try to send a newsletter to a group I get this error:

"Mail Send Error: Message body empty."

The obvious first question would be, "Do you have content in your newsletter?" The answer is "yes."

I have also tried the following with no success:

- Changed theme to 2012 (from Headway 2.0.14)
- Tried php mail instead of SMTP

Any help would be greatly appreciated. I need to get some messages out yesterday.

Thanks,

Danny Nelson