For security purposes I do not download files provided by anyone, sorry. I exported an existing local image to DCM and was able to confirm your issue. This is due to the strict mimetype check on download, but it's not really necessary. The below quickfix will resolve it and has been implemented for next release and nightly.
IN: components/com_comprofiler/plugin/user/plug_cbgallery/cbgallery.php
ON: Line 949 - 955
FROM:
Code:
$fileMime = $this->getMimeType();
if ( $fileMime == 'application/octet-stream' ) {
header( 'HTTP/1.0 406 Not Acceptable' );
exit();
}
TO:
Code:
$fileMime = $this->getMimeType();
forge.joomlapolis.com/issues/5453