1.2.3 No File Extension Found for File
This is an uncommon error that indicates that the name of the file you are attempting to download does not contain a file extension (such as .xls, .gif, or .mb). The reason for this error may be one of many. This error will only occur if you are attempting to download a single file, because the mime type of the file must be known in order to display the download dialog box in your browser.
This is a fatal error, and you will unfortunately be unable to download the specified file.
The webmaster is always notified of this type of error and will work on resolving this problem.