Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a 3 year old MacBook Pro and lately I've been getting an error message when I try to download something to my machine using Firefox. This is what it says:

Download error

/Users/scarletriley/Downloads/the name of document goes here- no spaces of course! could not be opened, because an unknown error occurred.

Try saving to a disk first and then opening the file.

What does this mean, and what should I do to fix it?

It downloads fine when using Safari.

share|improve this question
How many space left do you have on your drive? – Arko Mar 29 '10 at 13:09
(Spaces are not a problem on a Mac.) – Arjan Mar 29 '10 at 13:17
What browsers did you try? – Arjan Mar 29 '10 at 13:20
I have about 25 g on my hard drive, and I have tried it in Firefox. I just tried it in Safari, and it brought up the pdf, which I was then able to Save As to my desktop. – Scarlet Riley Mar 29 '10 at 13:45

Searching on google, i found this page on the Firefox support pages:

Choose a valid download folder in Safari Preferences

If you receive the error [filename] could not be saved, because an unknown error occurred, your problem might be caused by an interaction with the Safari browser and your operating system.

To fix the problem, open Safari's Preferences and change the Save downloaded files to: setting to a valid folder (such as your Desktop). Then restart Firefox.

It may help you fix your problem with Firefox.

share|improve this answer
@arko: instead of just including a link to the possible solution, please include some info -- a summary of the link, basic steps to fix, etc. that makes for a much more useful answer than "i found this page", especially for pages that might be moved or relocated in the future. – quack quixote Mar 29 '10 at 14:28
Good point, wondering why i didn't do it... Thanks for the edit. – Arko Mar 29 '10 at 15:00

FIRST Install a new version of Acrobat.


  1. Go To Firefox, Preferences
  2. Click the Applications tab
  3. Scroll down to PDF File
  4. Under Action click on the drop down menu next to it.
  5. Click Use other...
  6. Select the NEW VERSION of Acrobat that you just installed.
share|improve this answer

You must log in to answer this question.