What causes the Authentication Required popup message box on the app/home page?

Environment:

Customer Portal, Images
Oracle B2C Service, All Versions

Resolution:

You have a url that requires a login within your pages.

For example:

<img src="http://<.VHOSTNAME>/dav/cp/customer/assets/images/image.type

Any of your URL's that require you to login to access will need to be changed to

<img src="/euf/assets/images/image.type