Create Popular Tags block

A. Create Pupolar tags view

Step 1 Go to Structure > Views. Create Popular Tags view with following settings:

Step 2 Click "Continue and edit" button. A new popup is opened with following properties:

Step 3 At Relationships area, Click add button to add " Content: Taxonomy terms on node " field with following properties:

Step 4 At Use Aggregation select "Yes"

Step 5 At FIELDS area, Click add button to add " Taxonomy term: Name " field with following properties:

Step 6 At Sort Criterion area, Click add Content: Nid field with following properties:

Then Remove Content: Post date (desc) Field

Step 7 At FORMAT area, set following properties:

Step 8 Save view

B. Assign View: Popular tags block

Step 1 Go to Structure > Blocks

Step 2 Find View: Popular tags and click configure link, set following properties:

Step 3 Click "Save block" button.