Thumbnail URLs that cannot display or convert/resize fail silently

[Peter Davison]

When defining a URL for an online source thumbnail, if the URL is malformed or the image returned doesn't fit the thumbnail image specifications, the conversion fails silently and the default thumbnail is displayed.

It would be nice to provide some instructions as to what the valid thumbnail specs are in the console. In the media browser it would be nice if it could display some kind of indication that the thumbnail could not be loaded - perhaps a different default icon maybe with a tooltip describing that the specified icon could not be loaded and what the problem was with the specified URL.