
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.
I'm here to teach you the easiest way to fix that error. Come and follow what I'm going to teach you to fix that.
Step 1. Go to the blogger dashboard and find Theme and click.
Step 2. After you click on that, look for the drop down menu like in the picture.

Step 3. and when you're in edit html like in the picture, just copy the code I'll put in and copy paste it like in the picture.

CODE HTML
b:js='false'
and that's how easy it is to fix the error in blogger's widgets.js.
Please try this link, Pagespeed it's already fixed, thank you very much.