The error occurs on trying to change from the http site to the secure https site.
some servers have a seperate upload folder for the http site versus the secured https site.
where you are using PayPal payments pro, it strongly recommended that you use the https address for the checkout, you will need to uplaod the power store files to the correct directory on the server for the https address, contact your host if you are unsure where that is.
for the time being, i have disabled the redirect to the https server by editing the webassist/plugins/checkout_form.php page and commenting the following code:
/*if ((empty($_SERVER['HTTPS']) || $_SERVER['HTTPS']=="off") && !isset($_POST["Checkout_x"]) && !isset($_POST["Checkout"]) && (time() - $_SESSION['WA_HTTPS_Redirect']) > 8) {
if (!isset($_SERVER['REQUEST_URI'])) $_SERVER['REQUEST_URI'] = $_SERVER['PHP_SELF'];
$testRedirect = "https://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
$c = curl_init();
curl_setopt($c, CURLOPT_URL, $testRedirect);
curl_setopt($c, CURLOPT_TIMEOUT, 90);
curl_setopt($c, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($c, CURLOPT_SSL_VERIFYHOST, 0);
$result = curl_exec($c);
if ($result) {
$_SESSION['WA_HTTPS_Redirect'] = time();
header("location: ".$testRedirect);
die();
}
}*/
once you have the files uploaded to the https location, you should uncomment that code.