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Firefox saving Adobe Acrobat Document as unknown file type

  • 3 cavab
  • 1 has this problem
  • 16 views
  • Last reply by cor-el

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I'm attempting to download files from a website. They appear to be PDF files, and with the Applications setting under Options set to use with Adobe Acrobat or preview with Firefox, it will open up as a PDF. However, if I try to directly save the file, it saves as an unknown file type.

I'm attempting to download files from a website. They appear to be PDF files, and with the Applications setting under Options set to use with Adobe Acrobat or preview with Firefox, it will open up as a PDF. However, if I try to directly save the file, it saves as an unknown file type.

All Replies (3)

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You will have to add the .pdf file extension yourself is Firefox leave this file extension blank to make Windows recognize the file as a PDF file.

Try rename/remove the handlers.json and remove the previously used mimeTypes.rdf file in the Firefox profile folder to reset all file actions.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

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Thank you for the response, I did remove the previous mimeTypes.rdf and handlers.json yesterday, which did reset all the actions in Applications.

Is there a way to edit either of those to have Firefox automatically append the ".pdf" suffix to the file when saving? The site in particular has a list of documents we are downloading and combining into one document for later viewing. I was attempting to find a "one click" solution to download, rather than having to open in the PDF previewer or Acrobat and "Saving as..." or having to rename each individual file after saving.

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If this still happens with a freshly created handlers.json file then it is more likely a problem with related Windows Registry keys (HKCR\.pdf or a linked MIME database key).

  • HKEY_CLASSES_ROOT\.pdf
  • HKEY_CLASSES_ROOT\MIME\Database\Content Type\