36 Replies Latest reply on Nov 10, 2008 5:54 PM by (Jerry_Lai)

    Adobe 8 - Unexpected Corrupt or incorrect file type warning when viewing a PDF file from the Web


      On downloading a PDF file from my web site using Adobe 8 on the client machine I expect the file to open automatically however I receive encounter the "File Download" dialog. It has the following warning message: "The file you are downloading cannot be opened by the default program. It is either corrupted or it has an incorrect file type. As a security precaution, it is recommended that you cancel the download."

      This issue did not occur within previously tested versions of Adobe Reader (e.g. Version 5.1).

      On investigating the issue I discovered the factor that results in Adobe 8 failing to open the file automatically is the Content-Type = "application/pdf; Charset=utf-8". However, if I intercept the response and alter the Content-Type to contain only "application/pdf;" the issue on Adobe 8 does not occur.

      I have even tested when the Content-Type contains an empty Charset (i.e. "application/pdf; Charset=") but this issue still occurs. In addition setting the Charset to other encodings (e.g. "ISO-LATIN-7", "iso-8859-1") the issue occurs.

      1. Why is it necessary for Adobe 8 when opening PDF files from the web to expect no Charset within the Content-Type?
      2. If this was not an issue within previous versions of Adobe surly this is a bug?

      Since I cannot ensure that the Response's Content-Type does not contain a Charset at all please can someone suggest either a work-around or more importantly a solution to the issue?

      Please Note:-
      1. Within Adobe, Edit -> Preferences -> Internet option it's compulsory for our users to have "Display PDF in browser" ticked!
      2. We cannot prevent a Charset from being present within the Content-Type of the response sent to the client, hence this issue.

      Many Thanks in advance,