I was previewing an email and the email had a button(2 rows of words) with all white letters and was able to be connected/linked to a document. When the email was sent, the top row was white and the bottom was black. Only the top row of words was linked to the document but the bottom row wasn't. There was no way to know about the error until the email was sent out, and there was no way to correct it because it was showing correctly before it was sent.
Thank you for reaching out for help in the Community! We're sorry to hear the preview function did work properly and the button also didn't work in your email when it was live sent. We'd like research this issue on your account and see why it occurred so we can hopefully help you prevent it from happening in the future.
If you can, please an email to social_support(at)constantcontact(dot)com with your username, the name of the affected email campaign, and a reference to this post and we will look in to what caused this issue to occur for you.