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Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

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New User

Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

When I try to open attachments with .xlsx file extensions, Firefox identifies as a Firefox HTML document and the "open file" window does not show Excel as an option - when I try to Browse to Excel the window does not open to "my programs" where I might be able be able to designate the correct association. (it shows "Program Data" and "Program files" but these don't work to make the association. The file will save ok but, I want to be able to open them as I can easily do in IE. Is the only solution to give up on Firefox and go back to IE?

6 REPLIES
SUMO Contributor

Re: Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

Hello GWat ,try to delete the mimeTypes.rdf file in the Firefox profile folder to reset all file actions to default and check firefox again.

(A new file created again when starts firefox or when the application first needs to write to the file)


thank you

Senior User

Re: Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

Hello,

The following steps should resolve this:

  1. Click on the 'Firefox' button in the top left hand corner
  2. Select 'Options'
  3. Go to the 'Applications' Tab
  4. In the 'Content Type' column look for Excel or XLSX.
  5. Change the value in the 'Action' column to 'Use Microsoft Excel'

See my screenshot for an illustration of the change.

Please let me know if that doesn't help for any reason.

2013-07-16-07-40-26-44a50f.png
New User

Re: Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

I found and deleted the mimeTypes.rdf file and closed and reopened Firefox, and then tried opening the attached file, but again it thinks it is a Firefox HTML document and does not give Excel as a choice for programs to open it (shows graphics type programs that can open HTML's) any of those shown just open a page of garbage text and symbols. As I mentioned I do not see that the Browse tab takes me to an Excel choice.

New User

Re: Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

When I get to the content type window, there is no reference to Excel or .xlsx or anything similar, so I cannot change anything in the Action choice..

Site Moderator

Re: Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

You will have to make sure to add the correct file extension when saving the file if Firefox doesn't do this automatically.

New User

Re: Firefox incorrectly identifies .xlsx attachments as Firefox HTML documents

I'm not saving these files - in this case it is the Society of Automotive Engineers that is saving the files. And remember that the same files open with no problem in IE.