If your installed Edu X theme version is older than the latest version of Edu X, We recommend to update your theme. New version can have new features, fix for known bugs and other improvements.
https://www.drupar.com/doc/thex/update-theme
How To Update Edu-X Theme
Please follow below steps to update Edu-X theme.
Step 1: Download Theme
You can download latest version of Edu-X theme from project page:
https://www.drupal.org/project/edux
Step 2
Put your website in Maintenance mode.
Navigate to:
Home 
Administration Configuration Development Maintenance mode
example.com/admin/config/development/maintenance
Step 3: Upload Theme
Upload the new theme files by overwriting the existing files.
Step 4
Take your site out of maintenance mode.
Step 5: Save EduX Theme Settings
Navigate to:
Home Administration Appearance Appearance settings Edu X
example.com/admin/appearance/settings/edux
and re-save theme settings.
This is required because the new version can have new settings.
Step 6:
Clear Drupal cache.
Navigate to:
Home Administration Configuration Development Performance
example.com/admin/config/development/performance
Done!!!