in the universal email behavior, open the attachment tab, how are the attachments configured?
Send a screen shoot.
At this time, there is not a way around the message about needing to upload the connection file, the message comes from Power CMS Builder, there is a file that gets uploaded to the server to communicate with the database, for security reasons it is only good for a limited time, when it expires, a new version needs to be uploaded which is what happens when you click yes.