Help with navigation

Hi

I'm developing a course that  gives learners progressive access to Tabs to work their way through the content. This is all working fine.

Once learners have visited all Tabs and completed a quiz, they are given the option returning to the course. If they choose this option, I want all Tabs to then be active (not disabled) so learners can navigate to any part of the content.

This is where I've become stuck - for quite some time - and would greatly appreciate any help.

I've attached my story file if anyone would be willing to look at it.

(I've tried using variables and triggers to change the state of the tabs from disabled to normal and I'm not sure why this isn't working)

Many thanks

Lynne