Some users have received the error code bX-n8dcl6 when attempting to add an AdSense page element to their blog. This error code will appear if you have denied Blogger access to your AdSense account. You can correct this issue by doing the following:
1. Log into your AdSense account at https://www.google.com/adsense
2. Click on the 'My Account' tab
3. Click 'Account Access'
4. Click the 'Grant Access' link next to the Blogger website