Your client does not have permission to get URL

Problem: Many people get the following message after setting up google custom search on their blog:

"Forbidden Your client does not have permission to get URL /custom?

cx=xx18xxx54133xxx523xx3%3Ap7orhx6r8t8&q=xbczxbxzcvb&sa=Search&cof=GFNT

%3A%23666xx6%3BLH%3A55%3BCX%3ARECORD%2520SEARCH%3BDIV%3A%23cccccc

%3BFORID%3A1%3BL%3Ahttp%3A%2F%2Fwww.google.com%2Fcoop%2Fimages

%2Fgoogle_custom_search_sm.gif%3BLP%3A1%3BAH

%3Aleft&hl=en&client=pub-xxx41xxx092xxx7x from this server. (Client IP address: xxx.xx.xx.x)

We apologize for your inconvenience, but this request could not be processed.

Please click here to continue your search on Google."

Reason: This "Forbidden" message appears because your AdSense account either

1. hasn't been approved yet or 2. has been disapproved.
   

Solution: If your account has been disapproved, you'll receive an email from the Google AdSense team with instructions for how to resubmit your application.

In order to get your Custom Search Engine working in the meantime, you should disassociate your AdSense account trough the control panel. Try re-associating after your account is approved.