Thread:Project:Support desk/thumb directory and thumbs not being created

I'm using MediaWiki 1.21.1, PHP 5.3.26, MySQL I don't know. I've only recently installed MW and I'm new to everything that's going on. But there is a problem with my thumbnailer. When I upload an image to my wiki using Special:Upload, the file is uploaded successfully but no thumbnails are created. On the file description page of the file, no thumbnail is present, and when I click on any of the "available" resolutions listed under the filename, I get

Not Found The requested URL /w/images/thumb/1/11/myImage.jpg/320px-myImage.jpg was not found on this server. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

In LocalSettings.php I have $wgEnableUploads = true; $wgUseImageMagick = true; $wgImageMagickConvertCommand = "/usr/bin/convert"; And that path is correct.

Moreover, in the logs (which I've enabled) I see File::transform transformation deferred.BitmapHandler::doTransform: creating 320x213 thumbnail at mwstore://local-backend/local-thumb/1/11/myImage.jpg/320px-myImage.jpg using scaler im BitmapHandler::doTransform: Transforming later per flags.

But there is no "thumb" directory and there are no thumbs.

Please help!