sharing application to user not working

sharing application to user not working

hi,
I've been attempting to share my application with one other user.

When they sign into their account, the application does appear under their 'shared apps', however if they click on it, a message is displayed saying something like 'you are not permitted to access this application'.

In my account, under 'Share this Application' a message shows: 'You have not shared this application with anyone.' However when I add the email address of the other user, a warning message shows 'To share more users Upgrade your user plan', even though with a free account I'm entitled to 2 users.

Help!!

Thanks,
Amy.