I'm going to remove the button that creates a download link in File Manager because it is causing a lot of confusion. The fancy file manager introduced in mojoPortal 188.8.131.52 is based on QTfile and it already had this function for creating a link, however in mojoPortal this file manager is only allowed to be used by users with permissions and that includes the underlying file manager service. Since the link generated is not an actual url to the file but an url to the service page so that permissions can be enforced. I never intended anyone to use that link in content as an url to a file.
To get an url to a file for use in content you should use the editor and browse to the file from the image or media or link browser buttons in the wysiwyg editor.
The file manager doesn't know the difference between unprotected files and protected files, it treats all files as protected. In reality, files like image files or pdfs .doc or whatever is not a protected file and IIS will serve those files if the user knows the correct url. Other files like .config are protected by .NET and cannot be downloaded by direct http request even if you know the url. However file manager allows users to download any file whether protected or not if the user is allowed to use file manager, it is not meant for creating links to files for use in content, so this link generator button is causing confusion and leading to support issues. I will remove that button for the next release.
Hope it helps,