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When click on my firefox icon i get "404 Not Found. The requested URL was not found on this server" Worked fine until yesterday.

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  • 23 have this problem
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  • Last reply by timbonney

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I don't know what other details to give you. I can't get to my firefox start page. Firefox has not been deleted. I have downloaded and reinstalled several times and still get the same message when I try to open it.

I don't know what other details to give you. I can't get to my firefox start page. Firefox has not been deleted. I have downloaded and reinstalled several times and still get the same message when I try to open it.

Chosen solution

The locale part (en-US) seems to be missing from the URL:

Current Firefox versions use the build-in about:home page for the home page as posted above, so you can change the home page to that URL.

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Are you opening the home page when you start Firefox?

You can try to revert to the default about:home Home page.

See these articles for some suggestions:


Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

  • Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"

"Remove Cookies" from sites causing problems:

  • Tools > Options > Privacy > Cookies: "Show Cookies"
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I have cleared cache and cookies and that did not help. None of the links here seem appropriate.

I have discovered that when I click on the Firefox icon this address comes up and gives me the 404 "not found on this server" message:

http://start.mozilla.org/firefox?client=firefox-a&rls=org.mozilla:en-US:official

If if go into the address bar and delete everything except: "http://start.mozilla.org/" my Firefox home page then comes up. It is just a a pain in the behind to have to do that each time.

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Chosen Solution

The locale part (en-US) seems to be missing from the URL:

Current Firefox versions use the build-in about:home page for the home page as posted above, so you can change the home page to that URL.

Modified by cor-el

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Thanks!!, that is what is wrong (the missing "en-US". in the URL). Now tell me how to go into firefox and fix it. Obviously, I am not a tech savvy person.