'No Subscription Found'

Hi 

I am having the same issue as found in this thread: http://community.office365.com/en-us/forums/173/p/171949/500684.aspx

I get an error 'No Subscription Found' when trying to log in to Office Mobile App for iOS. We have had an E3 licence for over a year.

Licence:

I have gone to unassign the licence as suggested in the above thread however I am worried about this alert:

Can you please advise what data will be lost and if it this course of action is still approriate to resolve the 'No subscription found' issue when trying to log in to Office Mobile for iOS?

Thanks 

Campbell