Thank you Grey Parrots but that seems to be the problem – the background image displays in the custom theme (migrated from a MS Sharepoint site to WordPress a year ago) – the url to/for the image does not load into any other theme upon activation so I don’t think that the image’s url is discoverable via the media library. My guess is that there is a PHP line of code to locate and load the url but I have not found it and I do not know how or where to execute the line.
