Whenever I access a message at Yahoo Mail, a little window appears over the site:

Java Script

Error: document URL is undefined

My computer works with XP SP3, Firefox Browser. Avast and Spy-bot, all software fully-updated.

closed as off topic by Daniel Beck Jan 19 '13 at 16:50

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  • Does the Website still work even though the error pops up? What version of Firefox are you using? Have you tried disabling all add-ons in Firefox? Is your JavScript enabled in Firefox? – deiga Feb 26 '11 at 21:33

The dialog that appears with the title "JavaScript" is from the JavaScript interpreter running in your browser; the title is to let you know the source of the dialog (the idea is that it helps keep JavaScript dialogs from being hijacked by spammers or other miscreants).

The "text: Error: document URL is undefined" message is an error message from the JavaScript that Yahoo Mail is using to display your message. In short, it's most likely a problem with Yahoo Mail. It is also possible that it is a browser issue, since the browser is running the JavaScript. Try another browser, then try accessing that email account with another email reader.


JavaScript is a programming language that runs in a browser. The error is probably a result of Yahoo mail not working properly with your browser.

If you're using Firefox, there's a good chance you're using an outdated version (since Firefox has been updating so frequently these past few months!) Try updating your Firefox.

If Yahoo mail still seems to work, I wouldn't worry about the error message. Error messages happen all the time.

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