[Typo3] non-uploads/..resource did not exist error

[Peter Vines]

We have a production site which is suddenly displaying a strange error. 

When we add an image to a page, the thumbnail is visible in the BE however
the image is not visibile in the FE. I've looked at the typoscript messages
for the page using the admin panel and I'm getting error messages of the
form:

"Uploads/pics/imagename_01.jpg" is not a file (non-uploads/..resource, did
not exist).

We've changed our configuration so that uploads is in fileadmin/uploads and
the file does exist there. 

Thanks, Peter