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I get a "MIME Type" error when I try to upload a document using Firefox.

Thu, 05/20/2010 - 09:38 — ncole

When I try to upload my PDF attachment in Firefox, I get the following error: "An error prevented the successful upload of the attachment: Uploaded attachment must be in PDF format. MIME type of binary is not allowed.”

There are a handful of steps to fix this problem, which have been detailed here:

http://support.mozilla.com/en-US/kb/unable%20to%20download%20or%20save%20files#w_change-file-type-settings

Please contact support if the error persists after following these steps.

Change file type settings

If downloading certain file types does not work, check to make sure Firefox is not set to handle those file types differently from others. See the Managing file types for instructions on how to view and change how different file types are handled.

Reset download actions for all file types

To reset how all file types are handled by Firefox back to default:

  1. Open your profile folder:
    1. (Firefox 3.6): At the top of the Firefox window, click on the Help menu and select Troubleshooting Information.... The Troubleshooting Information tab will open.
    2. Under Application Basics, click on Open Containing Folder.
  2. From the menu at the top of the Firefox window, select File and then select the Exit menu item.
  3. Rename the mimeTypes.rdf file to mimeTypes.rdf.old .
  4. Restart Firefox.