I don't know why I can't add my adsense in the gadget of my Blogger it says "Please correct the errors on this form." I'm a blogger user for a long time and this is the first time I encountered this error. Anyways this error is when I created a new blogger account last week. Help will greatly appreciated. Thanks!
If you still can't add through the add features in google, try embed the adsense code using the embed html/script function in blogger.
If the gadget way is not working, try to paste the ad code directly into css template at appropriate place.
the best way to place ads on blogger is using widgets so google can show ads relevant to content you might have some errors in your template html