In case you place your Google adsense Code in the HTML Code areae, and it does not able to save it,
Please use this below tool to convert your code below place it. Then you will be able to save your Blogger Templage.

"Paste HTML Code in the Field below, press Convert Now Button to Getting Enclose Code"

Bank Main Site

"After You Click Convert Button You Will Get Another Converted Code that allow you to us"