With version 9 Tabs are displayed incorrectly when imported from version 8.x. Version 9 CSS Application themes have a new setting “position” under Tab–>Tab–>active/Inactive–>others in the theme editor. This is set to “absolute” by default causing the Tabs to all be displayed in the same position , which means they overlay each other. The workaround is to set the Position to “Relative” for both Active and Inactive.
CSS Editor in v9 :
[ATTACH=CONFIG]n78195[/ATTACH]
This is what it looks like in 8.x:
[ATTACH=CONFIG]n78196[/ATTACH]