[Solved] Incorrect content type for PDF file with Firefox

Question

Had the same problem with a .svg file.

Solved it by modifying the Mozilla Firefox mimeTypes.rdf file in the profile folder. (thx to Piotrs Link above)

For other people having a similar problem. This was caused due to a mistakenly set Content-Type in my PHP script. When first testing the script (it delivered a svg file indirectly via php) i had another Content-Type set in the header().

header("Content-Type: image/svg+xml"); //should have been
header("Content-Type: application/vnd.android.package-archive"); //was actually set

This now overruled the content type setting in the firefox mimeTypes.rdf file:

  <RDF:Description RDF:about="urn:mimetype:application/vnd.android.package-archive"
                   NC:value="application/vnd.android.package-archive"
                   NC:editable="true"
                   NC:fileExtensions="svg"
                   NC:description="Scalable Vector Graphics">
    <NC:handlerProp RDF:resource="urn:mimetype:handler:application/vnd.android.package-archive"/>
  </RDF:Description>

Probably because FF thinks its seeing a “new” file/filetype – and adding it to its config.

To fix this, you only need to delete the wrong XML section in the mimeTypes.rdf and restart FF of course.

Accepted Answer