Thread:Extension talk:Header Tabs/Header Tabs not working

Hi i have recently migrated mediawiki to v1.23. My preference settings are set to default and i can see the installed version of HeaderTabs in Version page.

The problem is, header tabs are not displayed, instead the content is displayed as a long list instead of being displayed in tabs.

However on my development machine it works perfectly fine where the version of mediawiki and HeaderTabs are same(only difference is in version of php, MySql and few other extension).

Currently i'm using HeaderTabs v1.0.1 and have tried various other versions like v0.9, 0.10, 0.1.0. but it's still not working. I have no clue what to do further. Can you please help.