http-fout 406 niet geaccepteerd

Heb dit nog niet voorgehad met een script.waarden worden ingevuld door design.php en dienen te worden geretourneerd door EditDesign.php dat zich in een andere folder bevindt
inhoud van dit script:
<<<?php

include ("tekst_functies.php");

$testName = $_POST['testName'];
$testName = str_replace (" ", "", $testName);

$siteTitle = $_POST['siteTitle'];
txtCreate("../design", "siteTitle", "$siteTitle");

$headerImg = $_POST['headerImg'];
txtCreate("../design", "headerImg", "$headerImg");

$headerImg_landscape = $_POST['headerImg_landscape'];
txtCreate("../design", "headerImg_landscape", "$headerImg_landscape");

$appIcon = $_POST['appIcon'];
txtCreate("../design", "appIcon", "$appIcon");

$appScreen = $_POST['appScreen'];
txtCreate("../design", "appScreen", "$appScreen");

$navColor = $_POST['navColor'];
txtCreate("../design", "navColor", "$navColor");

$navStyle = $_POST['navStyle'];
txtCreate("../design", "navStyle", "$navStyle");

$footerColor = $_POST['footerColor'];
txtCreate("../design", "footerColor", "$footerColor");

$socialHeadline = $_POST['socialHeadline'];
txtCreate("../design", "socialHeadline", "$socialHeadline");

$socialBar = $_POST['socialBar'];
txtCreate("../design", "socialBar", "$socialBar");

$sPhoneCheck = $_POST['sPhoneCheck'];
txtCreate("../design", "sPhoneCheck", "$sPhoneCheck");

$sPhone = $_POST['sPhone'];
txtCreate("../design", "sPhone", "$sPhone");

$sEmailCheck = $_POST['sEmailCheck'];
txtCreate("../design", "sEmailCheck", "$sEmailCheck");

$sEmail = $_POST['sEmail'];
txtCreate("../design", "sEmail", "$sEmail");

$sFBCheck = $_POST['sFBCheck'];
txtCreate("../design", "sFBCheck", "$sFBCheck");

$sFB = $_POST['sFB'];
txtCreate("../design", "sFB", "$sFB");

$sTwitterCheck = $_POST['sTwitterCheck'];
txtCreate("../design", "sTwitterCheck", "$sTwitterCheck");

$sTwitter = $_POST['sTwitter'];
txtCreate("../design", "sTwitter", "$sTwitter");

$sMapCheck = $_POST['sMapCheck'];
txtCreate("../design", "sMapCheck", "$sMapCheck");

$sMap = $_POST['sMap'];
txtCreate("../design", "sMap", "$sMap");

$footerInfo = $_POST['footerInfo'];
txtCreate("../design", "footerInfo", "$footerInfo");

$viewSiteTEXT = $_POST['viewSiteTEXT'];
txtCreate("../design", "viewSiteTEXT", "$viewSiteTEXT");

$viewSiteURL = $_POST['viewSiteURL'];
txtCreate("../design", "viewSiteURL", "$viewSiteURL");

header('Location: ../design.php');
?>
kan iemand mij helpen waarom deze fout?
met dank
Pierre