I am sorry to hear that you have been experiencing error messages while creating your email campaigns and saving them. I can understand how beneficial it would be to create and design your email campaigns without interruption. I will be happy to take a look into this further for you. Could you please provide the title of the email campaign you are working on, what action you're performing before saving the changes (e.g. editing a text block, replacing an image, changing font color, etc.), what browser you are using or have used, a reference to this post and email all this information to social_support(at)constantcontact(dot)com? Thank you!