The changes made are usually from tutorials found on the web written by some guy you don't even know, telling you to paste a code into your template. (lol ok i'm taking this too far)
What i'm trying to say is - Changes made to your blog can sometimes have negative effects and when CTRL Z cannot help you, a Restore can come to your rescue by uploading a backup you made before the change..
- Log-in to the Blogger dashboard and Click the Template Tab
- Click Backup / Restore Button at the Top-Right corner of the page
- To perform a Backup, Click the "Download Full Template" option
- To perform a Restore of a downloaded Backup, Click the Browse option and upload the backup template.(See Image below).
The Upload a Template Browse Button is also used to Install a Custom Blogger template
Illustration of Blogger Template Backup / RestoreHappy Blogging...