Bill,
I'm getting a null (blank) page.
What program are you using to open the book on your Mac?
My copy that was downloaded after purchase opens fine on my iMac running 10.12.4 Sierra, with Adobe Acrobat Pro and Adobe Acrobat Reader. However, it does what just yours does using Preview.
Try downloading the free Acrobat Reader DC from this URL: https://get.adobe.com/reader/
This one opens the password-protected pdf without any issues.