In Internet Explorer, when you click on a link to a pdf file, you get the error message “Adobe Reader could not open ‘filename.fdf’ because it is either not a supported file type or because the file has been corrupted.”

This error is due to an issue with Adobe Acrobat viewing PDF files in a web browser.

Try the following:

1. Open Internet Explorer, go to Tools -> Internet Options and on the General tab to erase all temporary files, cookies and history data.
2. Under Internet Explorer -> Tools -> Internet Options, on the General tab click on Settings and make sure you select the option “Automatically” for checking for newer versions of the stored pages. Then attempt to open the PDC file again.
3. If solutions 1 and 2 do not work then uninstall Adobe Acrobat, then reinstall it again.
It seems that Acrobat 6 is more prone to this error so upgrading to Acrobat 7 may solve the problem.