Test admin you created for me can not add new coupons too. Quick checking shows, that You have ‘Activate “Create Post/Page” capability’ option active. It turned on automatically with “Activate user access management to editing selected posts and pages” together. But “Administrator” role does not have ‘create_posts’ and ‘create_pages’ capabilities included. This is the reason of the problem. Administrators who may add new coupons has those capabilities added directly to their users.
After I added ‘create_posts’ and ‘create_pages’ capabilities to the “Administrator” role, test admin (you created for me) can add new coupons. I’m sure that it will be the same for the rest administrators.
