Sometimes problems like this are caused by "hiccups" on the Christianbook.com web server or on the Internet. With this in mind, you may want to retry whatever it is you just did in a little while.
If the problem keeps happening, you can contact the staff at Christianbook.com to let us know about it. Just send an email message to firstname.lastname@example.org including the details of what you were trying to do when the error occurred. Also, be sure to include the following error message in your email, as it will greatly assist us in diagnosing and solving the problem
Could not locate user ticket in request headers.* 42 *
Thank you, and God bless.
-- Your Friends at Christianbook.com