I apologize you're having this experience! I can understand how important it is to easily work in your account. Are you having this experience in more than one campaign? Or even in more than one browser? If you have not yet tested creating your email in a different browser or a private/incognito window I would suggest doing so. It's a great step to see if this is browser related as there have been cases where 3rd party add-ons could affect how Constant Contact works. If you are still having this experience in a different browser please share with us a screenshot of the exact error message you are receiving. We would be happy to look into this further for you.