MultiPowUpload 3.4
Troubleshooting
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Troubleshooting

Here you can find most often errors and problems that can occur while working with MultiPowUpload. Some articles are joined in groups and relate to the technology of the file processing code on server side.

Any HTTP error:

Read the following paragraph in case of any problems:
We advise to install HTTP Sniffer for testing period to see server replies and errors. You may use an excellent HTTP Analyzer (15 days trial) or free Wireshark. HTTP Sniffer is also useful for seeing which data MultiPowUpload transfers and their format.

All the HTTP errors and their short descriptions can be seen at w3.org website.

Lost session or authentication info

It is a known Flash Player bug, but Adobe still can't fix it.
FlashPlayer in non-IE browsers doesn't pass the cookies during the upload. Therefore, sessions are different on the page with Flash and upload script.

Workaround:
MultiPowUpload sends cookies (and session ID) in "MultiPowUpload_browserCookie" Form filed value, but on server side you need some code that parses this value and sets to Cookies collection. MultiPowUpload includes ASP.NET (Global.asax in the root) and PHP samples.

There is another problem related to this bug: if the cookies marked as HTTPOnly on the web server, MultIPowUpload can't access them (because it uses JavaScript to get browser cookies).

If you have HTTPOnly mode enabled on your web server (most often on IIS server with ASP.NET 2.x and later), you should disable it in order to allow MultiPowUpload access cookies.

Solution for IIS server with ASP.NET:

<httpCookies httpOnlyCookies="false" />
It is a parameter in the web.config file of your application, but for some reason this parameter won't work with .NET 2.0 Here is the sample global.asax file (place it into the root folder of your application) that marks all cookies as non-httponly:
<script runat="server">
void Application_EndRequest(object sender, EventArgs e) {
if(Response.Cookies.Count > 0)
       foreach(string s in Response.Cookies.AllKeys)        
               Response.Cookies[s].HttpOnly = false;
}
</script>

Solution for PHP (5.2 or above):
Set the value of the session.cookie_httponly parameter to false.
ini_set("session.cookie_httponly", 0);

 

ASP (ASP.OLD) file processing script

Error 403
See solution here http://support.microsoft.com/kb/327659

Write Permissions to UploadedFiles\ folder
Error like "Access to the path "C:\Inetpub\wwwroot\Upload\UploadedFiles\myfile.jpg" is denied"

The directory where the uploaded files will be saved to on the web server must have Read, Write, and Delete NTFS permissions for the Anonymous or authenticated user (if the Windows authentication is used):
Right-click the file in the Explorer, choose "Properties" and select the Security tab. Click "Add" to add an appropriate user or a group. Highlight the necessary account, and check the boxes for the desired access.

ASP.NET file processing script

Create a web application in the folder with the script
Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.

ASP.NET code works only in folders on the server with created "web application". To create it: Open Control panel->Administrative tools-> Internet Information Services->Expand "Default web site", right click the necessary folder and select "Properties" in the context menu. In the folder properties dialog box, open "Directory" tab and click "Create" button (create Application), click "ok".

Write Permissions to UploadedFiles\ folder
Error like "Access to the path "C:\Inetpub\wwwroot\Upload\UploadedFiles\myfile.jpg" is denied"

You should grant NETWORK SERVICE (for IIS 6) or ASPNET (IIS6) or other necessary account, write an access to a folder where uploaded files will be saved, right-click the file in the Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or a group. Highlight the necessary account, and check the boxes for the desired access.

IIS7 ASP.NET file processing script

HTTP Error 404.13 - Not Found
Description: The request filtering module is configured to deny a request that exceeds the request content length.

Upload files greater than 30 MB

By default, requestFiltering that has MaxAllowedContentLength property is enabled in IIS 7. It specifies, in bytes, the maximum length of the content in a request. The default is 30000000 (approximately 30 megabytes). To change this value, you must include the following code in your Web.config file if you want to apply this setting only to you application. If you want to change this setting for all of the computer and not just this ASP.NET application, you must modify the Machine.config file. By default, the element is set to the following parameters in the Machine.config file: The Machine.config file is located in the \System Root\Microsoft.NET\Framework\Version Number\CONFIG directory.

If you have an error that requestFiltering cannot be overriden you must edit the mashine.config file and change the string
<section name="requestFiltering" overrideModeDefault="Deny" />
to <section name="requestFiltering" overrideModeDefault="Allow" />

PHP

Information related to files upload in PHP
You can find a lot of information related to the file upload in the PHP code at this website http://de3.php.net/manual/en/features.file-upload.php
By default, uploadfiles.php script shows an error constant. See the description of all constants related to the upload at http://php.net/manual/en/features.file-upload.errors.php

php.ini settings related to upload

The most common cause of problems related to the file uploads is PHP itself. The following php.ini settings effect the file uploads:

file_uploads boolean

Name

Default

Changeable

Changelog

file_uploads

"1"

PHP_INI_SYSTEM

PHP_INI_ALL in PHP <= 4.2.3. Available since PHP 4.0.3


This parameter has to be set to 1 to accept file uploads, value 0 is not to accept the file uploads. Default value is 1.

post_max_size integer

Name

Default

Changeable

Changelog

post_max_size

"8M"

PHP_INI_PERDIR

PHP_INI_SYSTEM in PHP <= 4.2.3. Available since PHP 4.0.3



This is the maximum size of a POST request that PHP will accept. The default for PHP 4.3.x is 8M. If the file(s) you are trying to upload have a single or combined size over this value, PHP will exit. It affects the total post data. For example, if it has been set to 8M and you are uploading four 3M files, PHP will not accept the files. You could, however, upload the four 3M files individually without a problem with this setting.
To upload large files, this value must be larger than upload_max_filesize.
If the memory limit is enabled by your configure script, memory_limit also affects the file uploading. Generally speaking, memory_limit should be larger than post_max_size.
If the size of post data is greater than post_max_size, the $_POST and $_FILES superglobals are empty. It can be tracked in various ways, e.g. by passing the $_GET variable to the script processing the data, i.e. <form action="edit.php?processed=1">, and then checking if $_GET['processed'] is set.
memory_limit integer

Name

Default

Changeable

Changelog

memory_limit

"128M"

PHP_INI_ALL

"8M" before PHP 5.2.0, "16M" in PHP 5.2.0

It sets the maximum amount of memory in bytes that a script is allowed to allocate. It helps to prevent poorly written scripts for eating up all available memory on a server. Note that to have no memory limit, set this directive to -1.

upload_max_filesize integer

Name

Default

Changeable

Changelog

upload_max_filesize

"2M"

PHP_INI_PERDIR

PHP_INI_ALL in PHP <= 4.2.3.



This is the maximum size of an individual uploaded file. The default for PHP 4.3.x is 2M.

max_input_time ineger


Name

Default

Changeable

Changelog

max_input_time

"-1"

PHP_INI_PERDIR

Available since PHP 4.3.0.


This is the maximum time PHP will accept input in seconds.

upload_tmp_dir string

Name

Default

Changeable

Changelog

upload_tmp_dir

NULL

PHP_INI_SYSTEM

 

The temporary directory used for storing files when doing file upload. It must be writable by whatever user PHP is running. If non-specified PHP will use the system's default.


Definition of PHP_INI_* constants


Constant

Value

Meaning

PHP_INI_USER

1

Entry can be set in user scripts or in Windows registry

PHP_INI_PERDIR

2

Entry can be set in php.ini, .htaccess or httpd.conf

PHP_INI_SYSTEM

4

Entry can be set in php.ini or httpd.conf

PHP_INI_ALL

7

Entry can be set anywhere


Change Apache settings

If you do not have access to change php.ini and your website is running on apache, you may be able to include these settings in an .htaccess file. It is possible only if "AllowOverride Options" or "AllowOverride All" privileges have been set (by you, by your ISP, or by a system administrator) in httpd.conf.

If it is feasible, or if you want to try the solution on your own, create or edit a file named .htaccess (assuming you want a 6Mb max attachment size):
php_value post_max_size "7M"
php_value upload_max_filesize "6M"
php_value max_input_time "120"

Permissions

If it is a Window server, nothing is required and by default the window gives all permissions.

For Linux and Unix you have to set write (Chmod) permission to both temp and destination directories to allow uploaded files to be stored.