Overcoming Feedburner Error Message On Blogger - If you do not make any changes to your FeedBurner settings after adding your site, it will display an error message when visitors try to subscribe to your site.
The error message should look like this:
The settings for FeedBurner feed subscribe to emails are disabled by default and you must enable them directly from the Feedburner configuration page.
Here's how to fix this: Go to Feedburner site here
Select the blog to be in settings
Now find and open the tab Publicize
Click to enlarge image
In the left menu select the Email Subscriptions button click Activate
then click Save and finish
Now you have successfully activated your email subscription from Feedburner.
may be useful.