#StackBounty: #php #html #http-status-code-406 PHP – Not Acceptable – 406 – file could not be found on this server

Bounty: 50

I am getting this error

Not Acceptable

An appropriate representation of the requested resource
/admin/prc_res.php could not be found on this server.

Additionally, a 406 Not Acceptable error was encountered while trying
to use an ErrorDocument to handle the request.

There is a $_POST['additionalinfo'] (from html teaxtarea) which is giving me this error. If I remove this, code works fine.

But why I am getting 406 error?

My index1.php in unnat1ir.in/cdn/

<!doctype html>
<meta charset="utf-8">
<title>406 Error</title>
<p><form method="post" action="process.php">
<textarea name="test" rows="10" style="width:100%"></textarea><br>
<button type="submit">Check for 406 Error</button>
<p>This form is posted to <code>process.php</code>. In <code>process.php</code> I am just echo-ing <code>$_POST['test']</code> of the <code>textare with tinymce plugin</code>. <strong>If little amount of data is entered in textarea, no issues, BUT LARGE DATA will cause <code>406</code> error</strong></p>
<h1>Please check by inserting large <code>html</code> data </h1>

And process.php

ini_set("log_errors", 1);
ini_set("error_log", "err.txt");
<h1>The <code> echo ($_POST['test'])</code> is</h1>
<code><? echo htmlentities($_POST['test']); ?></code>

All the above codes working fine on localhost

Get this bounty!!!