Sometimes one sees the wrong icon next to a file in the Resources tool, this may also have the side effect of forcing the download of a file rather than opening it in the browser. This can be quite annoying.
I asked WebLearn developer Matthew Buckett about this and here is what he had to say about PDFs that were incorrectly attributed.
To fix the issue go into the Resources tool and for every file with the problem click on “Edit Details (Properties)” then scroll to the bottom of the page to find the File Type field and click “Change File Type”. Then from the first drop-down list select “application” and from the second select “pdf”. Then click save. The file should then download/open in all browser fine.
Background/Reasons: When a file is uploaded to WebLearn we get some additional bits of information as well as the actual file. One of those pieces of information is the MIME type, which is a value saying what the format of the contents of the file are. When file was uploaded into WebLearn, the user’s computer told WebLearn that the contents of the files were ‘text/unknown’, WebLearn saves this value and then when anyone download/opens the file the value is sent back to the browser to help it understand it. This mechanism allows files to open correctly when they don’t have a known extension.
To address the above problem, the user needs to fix the MIME type for all PDF files on his computer which should stop this problem from occurring in the future. One might be able to do this using the Finder or an application like http://www.rubicode.com/Software/RCDefaultApp/
Some browsers don’t trust the value in the MIME type and will also look at the file extension to determine how to handle it so the problem may not be evident with all browsers. Once the file is downloaded and saved to disk the MIME type information is lost and so the operating system uses the file extension to determine how to open the file.
Another way to workaround the problem is to put the files to upload in a zipfile then upload the zipfile and expand the zipfile in WebLearn. This way there isn’t any MIME type information about the PDF files when the ZIP is expanded so WebLearn should use the .pdf extension to set the MIME type and so get it correct.