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Getting 400/Bad Request error

  • 17 replies
  • 16 have this problem
  • 6 views
  • Last reply by FredMcD

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I've started getting a 400/Bad Request errors on various sites. I'm running FF 41.0. I cleared my cache/cookies, and it helped a little but still having issues. Some sites that don't work will work if you type the site differently. Some examples:

Doesn't work: www.youtube.com/ Works: https://www.youtube.com/

Doesn't work: Searching for anything in Amazon and this link http://www.amazon.com/Walking-God-through-Pain-Suffering/dp/0525952454/ref=tmm_hrd_title_0?ie=UTF8&qid=1418587605&sr=1-1 Works: This link for some reason and some others http://www.amazon.com/gp/product/1594483493/ref=gno_cart_title_0?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

Any ideas?

I've started getting a 400/Bad Request errors on various sites. I'm running FF 41.0. I cleared my cache/cookies, and it helped a little but still having issues. Some sites that don't work will work if you type the site differently. Some examples: Doesn't work: www.youtube.com/ Works: https://www.youtube.com/ Doesn't work: Searching for anything in Amazon and this link http://www.amazon.com/Walking-God-through-Pain-Suffering/dp/0525952454/ref=tmm_hrd_title_0?ie=UTF8&qid=1418587605&sr=1-1 Works: This link for some reason and some others http://www.amazon.com/gp/product/1594483493/ref=gno_cart_title_0?ie=UTF8&psc=1&smid=ATVPDKIKX0DER Any ideas?

All Replies (17)

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Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options)
key, and then starting Firefox. Is the problem still there?


Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

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Yes, still experience the same issue.

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This issue is usually caused by corrupted cookies.

Clear the cache and remove cookies only from websites that cause problems.

"Clear the Cache":

  • Firefox > Preferences > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

  • Firefox > Preferences > Privacy > "Use custom settings for history" > Cookies: "Show Cookies"

If clearing cookies didn't help then it is possible that the cookies.sqlite file that stores the cookies got corrupted.

Modified by cor-el

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It worked! Thanks!  :D

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It seems like this problem has resurfaced. Any other ideas?

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Remove History For One Site Open the History Manager <Control><Shift> H. In the search bar, enter the name of the site. Right click on one of the listings and select Forget About This Site. This should remove all information, including any passwords / settings.

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Did you try to delete the cookies.sqlite file in the Firefox profile folder?

You can use this button to go to the current Firefox profile folder:

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I've tried both of these but they only help temporarily.

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How long before it goes bad? Did you try the above again?

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Yes, I've tried it a few times. It last a couple of minutes, then goes bad again. For example, if I search for something on eBay, it doesn't work, I forget the site, it then works, search for something else, and then it breaks again.

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Do you have security software that might be causing this issue? What security software do you have?

Cookies shouldn't get corrupted that easily and that often.

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Sophos Anti-Virus (free version) and Malwarebytes Anti-Malware.

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As a test, disable all of your protection for a quick run. Any problem?

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Initially, it seems like that solved it.

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What are you using for protection? List everything.

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I have a Mac, so I have the Apple firewall enable. For Sophos, I turned off blocking to malicious sites and malicious downloads from website. I turned the Sophos stuff off and it seems to be better.

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Some protection programs don't work with each other. Disable one, enable the other and do a test run. After, switch them-around and try again.