Thank you for reaching out to the Constant Contact Community. I hope you are having a nice weekend.
I'm sorry to hear that you are having trouble adding an image that has been used before. I have a couple of questions that may help us troubleshoot. Can you send an email to social_support(at)constantcontact(dot)com with your username, the image you are trying to use, the name of your campaign, where you are trying to insert it, and a reference to this post along with any other information you think will be helpful and we will take a look at it?
Thank you for choosing Constant Contact. Have a great day!