Recent answers to Bad Request Your browser sent a request that this server could not understand. Size of a request header field exceeds server limit.https://support.mozilla.org/ar/questions/12906042020-06-10T12:02:00-07:00Please ignore spam replies about third-party support you may have received earlier and do not call a2020-06-10T12:02:00-07:00cor-elhttps://support.mozilla.org/ar/questions/1290604#answer-1322719<p>Please ignore spam replies about third-party support you may have received earlier and do not call a supplied phone number or send email.<br>This is the official support forum and we do not supply support by phone.
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<p>This issue can be caused by corrupted cookies.
</p><p>Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).
</p><p>"Remove the Cookies" for websites that cause problems:
</p>
<ul><li>Options/Preferences -&gt; Privacy &amp; Security<br>Cookies and Site Data: "Manage Data"
</li></ul>
<p>"Clear the Cache":
</p>
<ul><li>Options/Preferences -&gt; Privacy &amp; Security<br>Cookies and Site Data -&gt; Clear Data -&gt; Cached Web Content: Clear
</li></ul>
<p>If clearing cookies didn't help then it is possible that the cookies.sqlite file in the Firefox profile folder that stores the cookies got corrupted.
</p>
<ul><li>rename/remove <b>cookies.sqlite</b> (cookies.sqlite.old) and when present delete cookies.sqlite-shm and cookies.sqlite-wal in the Firefox profile folder with Firefox closed in case cookies.sqlite got corrupted.
</li></ul>
<p>You can use the button on the "Help -&gt; Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the <b>about:profiles</b> page.
</p>
<ul><li>Help -&gt; Troubleshooting Information -&gt; Profile Folder/Directory:<br>Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
</li><li><a href="https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data" rel="nofollow">https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data</a>
</li></ul>There is security software like Avast, Kaspersky,
BitDefender and ESET that intercept secure
connect2020-06-10T01:45:40-07:00fredmcd-hotmailhttps://support.mozilla.org/ar/questions/1290604#answer-1322491<p>There is security software like Avast, Kaspersky,
BitDefender and ESET that intercept secure
connection certificates and send their own.
</p><p><a href="https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can" rel="nofollow">https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can</a>
</p><p><a href="https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites" rel="nofollow">https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites</a>
</p><p><a href="https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message" rel="nofollow">https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message</a>
</p><p><a href="https://support.mozilla.org/en-US/kb/connection-untrusted-error-message" rel="nofollow">https://support.mozilla.org/en-US/kb/connection-untrusted-error-message</a>
</p><p><a href="https://support.mozilla.org/en-US/kb/websites-dont-load-troubleshoot-and-fix-errors?redirectlocale=en-US&amp;redirectslug=Error+loading+web+sites" rel="nofollow">Websites don't load - troubleshoot and fix error messages</a>
</p><p><a href="http://kb.mozillazine.org/Error_loading_websites" rel="nofollow">http://kb.mozillazine.org/Error_loading_websites</a>
</p><p><a href="https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean" rel="nofollow">What do the security warning codes mean</a>
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