400 status code indicates that the server cannot process the request due to client error.
The user receives an error message indicating that their request is incorrect and needs to be fixed.
GET / HTTP/1.1 Host: 1ba.com Accept: */* User-Agent: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; [email protected])
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html><head> <meta type="copyright" content="Copyright (C) 1996-2022 The Squid Software Foundation and contributors"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>ERROR: The requested URL could not be retrieved</title> <style type="text/css"><!-- /* * Copyright (C) 1996-2022 The Squid Software Foundation and contributors * * Squid software is distributed under GPLv2+ license and includes * contributions from numerous individuals and organizations. * Please see the COPYING and CONTRIBUTORS files for details. */ /* Stylesheet for Squid Error pages Adapted from design by Free CSS Templates http://www.freecsstemplates.org Released for free under a Creative Commons Attribution 2.5 License */ /* Page basics */ * { font-family: verdana, sans-serif; } html body { margin: 0; padding: 0; background: #efefef; font-size: 12px; color: #1e1e1e; } /* Page displayed title area */ #titles { margin-left: 15px; padding: 10px; padding-left: 100px; background: url('/squid-internal-static/icons/SN.png') no-repeat left; } /* initial title */ #titles h1 { color: #000000; } #titles h2 { color: #000000; } /* special event: FTP success page titles */ #titles ftpsuccess { background-color:#00ff00; width:100%; } /* Page displayed body content area */ #content { padding: 10px; background: #ffffff; } /* General text */ p { } /* error brief description */ #error p { } /* some data which may have caused the problem */ #data { } /* the error message received from the system or other software */ #sysmsg { } pre { } /* special event: FTP directory listing */ #dirmsg { font-family: courier, monospace; color: black; font-size: 10pt; } #dirlisting { margin-left: 2%; margin-right: 2%; } #dirlisting tr.entry td.icon,td.filename,td.size,td.date { border-bottom: groove; } #dirlisting td.size { width: 50px; text-align: right; padding-right: 5px; } /* horizontal lines */ hr { margin: 0; } /* page displayed footer area */ #footer { font-size: 9px; padding-left: 10px; } body :lang(fa) { direction: rtl; font-size: 100%; font-family: Tahoma, Roya, sans-serif; float: right; } :lang(he) { direction: rtl; } --></style> </head><body id="ERR_INVALID_URL"> <div id="titles"> <h1>ERROR</h1> <h2>The requested URL could not be retrieved</h2> </div> <hr> <div id="content"> <p>The following error was encountered while trying to retrieve the URL: <a href="/">/</a></p> <blockquote id="error"> <p><b>Invalid URL</b></p> </blockquote> <p>Some aspect of the requested URL is incorrect.</p> <p>Some possible problems are:</p> <ul> <li><p>Missing or incorrect access protocol (should be <q>http://</q> or similar)</p></li> <li><p>Missing hostname</p></li> <li><p>Illegal double-escape in the URL-Path</p></li> <li><p>Illegal character in hostname; underscores are not allowed.</p></li> </ul> <p>Your cache administrator is <a href="mailto:root?subject=CacheErrorInfo%20-%20ERR_INVALID_URL&body=CacheHost%3A%20host%0D%0AErrPage%3A%20ERR_INVALID_URL%0D%0AErr%3A%20%5Bnone%5D%0D%0ATimeStamp%3A%20Sun,%2020%20Apr%202025%2010%3A54%3A33%20GMT%0D%0A%0D%0AClientIP%3A%20135.181.60.100%0D%0A%0D%0AHTTP%20Request%3A%0D%0A%0D%0A%0D%0A">root</a>.</p> <br> </div> <hr> <div id="footer"> <p>Generated Sun, 20 Apr 2025 10:54:33 GMT by host (squid/5.5)</p> <!-- ERR_INVALID_URL --> </div> </body></html>