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Q320240: XCCC: Troubleshooting "HTTP 404" Error Messages in OWA 5.5

Article: Q320240
Product(s): Microsoft Exchange
Version(s): 5.5
Operating System(s): 
Keyword(s): 
Last Modified: 08-AUG-2002

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The information in this article applies to:

- Microsoft Outlook Web Access, version 5.5 
- Microsoft Outlook Web Access, version 5.5 Service Packs 1, 2, 3 
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SUMMARY
=======

If you use Microsoft Outlook Web Access (OWA), you may receive any of the
following "HTTP 404" error messages:

  HTTP/1.0 404 File Not Found

  -or-

  HTTP/1.0 404 Not Found

  -or-

  HTTP/1.0 404 Object Not Found

  -or-

  HTTP/1.0 404 Page Cannot Be Found

  -or-

  The page cannot be found. The page you are looking for might have been
  removed, had its name changed, or is temporarily unavailable

This article describes issues that may cause these error messages and how to
resolve these issues.

MORE INFORMATION
================

These error messages may be caused by issues with any of the following
features:

- DNS name resolution

- Proxy Server configuration

- Exchange virtual directory configuration

- Uniform Resource Locator (URL) creation

- The URLScan component of the Internet Information Server (IIS) Lockdown tool

The following sections describe how to resolve these issues.

DNS Name Resolution
-------------------

The error messages that are described in the "Symptoms" section may occur if the
computer on which you are running the Web browser is unable to resolve either of
the following server names that you type in the Address box:

- "http://<servername>/exchange" (without the quotation marks)

- "http://<fully_qualified_domain_name>/exchange" (without the quotation
  marks)

If you cannot resolve the name of your server over the Internet, you may have to
ask your Internet service provider (ISP) to create a DNS record for your server,
which matches the fully qualified domain name (FQDN) that you want to use to
access OWA.

If you cannot resolve the address on the internal network if you type the NetBIOS
server name in the Address box, you must create a valid HOST record for this
server on the DNS server that the client workstations are using for name
resolution.

Alternately, you can add an entry for the OWA server to the HOSTS file on the
workstation that is running the Web browser. For Microsoft Windows NT, Microsoft
Windows 2000, and Microsoft Windows XP, this file is located in the
<X>:\Winnt\System32\Drivers\Etc folder (where <X> is the drive on
which the Windows folder is located). In Microsoft Windows 95, Microsoft Windows
98, Microsoft Windows 98 Second Edition, and Microsoft Windows Millennium
Edition (Me), this file is located in the <X>:\Windows folder. This file
is called "HOSTS" and it does not have a file extension (a sample file
"HOSTS.SAM" may exist in the folder).

To add an entry for the OWA server to the HOSTS file on the workstation that is
running the Web browser:

1. Start Microsoft Notepad, and then open the HOSTS file.

2. Use the following format to add an entry for the OWA server:

  <ip_address><servername>

3. Close and save file.

  Do not give the file a file name extension.

4. If you are using Windows 2000 or Windows XP, type the following command from
  a command prompt, and then press ENTER:

  "ipconfig /flushdns" (without the quotation marks)

Proxy Server Configuration
--------------------------

You may receive an "HTTP 404" error message if OWA and Proxy Server are running
on separate computers and you did not configure the Web Publishing feature of
Proxy Server to forward requests to the OWA server.

To resolve this issue, enable Web Publishing to send requests to another Web
server:

1. Start Internet Service Manager.

2. On the Action menu, click Web Proxy, and then click Properties.

3. Click the Publishing tab, and then click to select the "Enable Web
  Publishing" check box.

4. Click "Sent to another web server".

5. Type either the internal IP address or the NetBIOS name of the OWA server.

  You can also use the FQDN as long as the name can be resolved by Proxy Server
  to the internal IP address.

For additional information about this issue or if more than one Web server
exists, click the article number below to view the article in the Microsoft
Knowledge Base:

  Q207655 Setting Up Web Publishing and OWA Access Through a Proxy

Exchange Virtual Directory Configuration
----------------------------------------

You may receive an "HTTP 404" error message if the Exchange virtual directory
folder is missing or if you renamed it under the Web site to which the users are
connecting.

To resolve this issue:

1. Run the Exchange Setup program from the installation CD.

2. Use the Add/Remove option to see if the OWA entry has a check mark next to
  it.

  If the OWA entry has a check mark next to it, cancel Setup. If it does not,
  place a check mark in the box (leave the other options as they are), and then
  continue Setup. OWA is added to this server.

3. Start Internet Service Manager.

4. Expand the Web site in which you installed OWA.

  In a typical configuration, OWA is located under "Default Web Site".

5. Verify that the Exchange virtual directory is listed under the Web site.

  If the Exchange virtual directory is listed under the Web site, go to step 3.
  If it is not listed, you must create an Exchange virtual directory.

6. Right-click Exchange Virtual Directory, and then click Properties.

7. Confirm that the local path is set to <X>:\Exchsrvr\Webdata (where
  <X> is the drive in which you installed Exchange 2000).

8. Make sure that the access permissions are set to Read-enabled.

9. Under the Application Settings section, confirm that the Permissions setting
  is set to Execute (including script).

10. Confirm the first of the three buttons that is listed in this section is
  labeled Remove instead of Create.

  If the first button is labeled Create, click this button to change the label
  to Remove.

11. Click the Documents tab, and then confirm that the Enable Default Document
  check box has been selected.

12. Confirm that "default.htm" and "default.asp" are listed in the documents
  list.

13. Click the Directory Security tab, click Edit in the "Anonymous Access and
  Authentication Control" section.

14. Confirm that the check box next to Allow Anonymous Access has been selected.

15. Configure either Basic Authentication or Windows NT Challenge/Response.

  To determine the authentication method that you want to use, find out whether
  the users will be accessing OWA from the Internet or through a proxy server
  or a firewall. If users access OWA through a proxy server or a firewall, use
  the Basic Authentication method.

16. Save and close the virtual directory properties.

17. Right-click Default Web Site, and then click Properties.

18. Click the ISAPI Filters tab.

19. Confirm that "exchfilt" is displayed in the ISAPI Filters list.

  If this filter is not listed, click Add, and then browse to the
  <X>:\Winnt\System32\Exchfilt.dll file (where <X> is the drive in
  which you installed Windows).

20. Click Save, and then click Close.

URL Creation
------------

You may receive an "HTTP 404" error message if the URL address that OWA builds to
open the message is incorrect. OWA calculates and checks the files in the
Webdata folder to determine if the object is a file or folder. If you set flags
such as "Archive" or "Compressed" on the folder, OWA may not calculate the
folder correctly. In this situation, OWA produces the wrong URL.

To determine if you are experiencing this issue:

1. Reproduce the error message.

2. In the error message dialog box, point to Toolbars on the View menu, and then
  click Address Bar.

  If OWA creates an incorrect URL, the following URL is displayed in the address
  bar:

  

  javascript:parent.openNewWindow("/exchange/forms/IPM.NotefrmRoot.asp?...

  The following URL is the correct URL:

  

  javascript:parent.openNewWindow("/exchange/forms/IPM/NotefrmRoot.asp?...

This problem only occurs on servers that are running Exchange Server 5.5 Service
Pack 1 (SP1). To resolve this problem, obtain the latest service pack for
Exchange Server 5.5. For additional information, click the following article
number to view the article in the Microsoft Knowledge Base:

  Q191014 How to Obtain the Latest Exchange Server 5.5 Service Pack

If you are experiencing this behavior on a later version of Exchange Server 5.5,
the file that controls this process (Cdohtml.dll) may not be registered or it
may be out of date. To resolve this issue:

1. Locate the Cdohtml.dll file on the hard disk.

  Typically, this file is in the <X>:\Exchsrvr\Bin folder.

2. Right-click the Cdohtml.dll file, and then click Properties.

3. Click the Version tab, and then view the Comments box.

  Confirm that the information in the Comments box describes the service pack
  level that you are currently running. If it does, go to step 4. If it does
  not, start the Services tool in Control Panel, stop the WWW Publishing
  Service, rename the existing Cdohtml.dll file to "cdohtml.old," and then copy
  the file from your latest service pack install point to the same folder.

4. From a command prompt, type the following command (where <x> is the
  drive in which you installed Exchange Server):

  "regsvr32 <x>:\exchsrvr\bin\cdohtml.dll" (without the quotation marks)

  You receive the following message:

  DllRegisterServer in x:\exchsrvr\bin\cdohtml.dll Succeeded.

5. Start the WWW Publishing Service.

The URLScan Component of the IIS Lockdown Tool
----------------------------------------------

If you are using OWA, you may not be able open messages that include certain
characters in the subject line.

This issue can occur on a server that is running URLScan (which is a component of
the IIS Lockdown tool). By default, URLScan blocks certain potentially harmful
characters in the URL. The following list describes the blocked characters and
the reason why they are blocked:

- Two periods (..): You cannot use folder traversals.

- A period and a backslash (./): You cannot use a trailing period on a folder.

- backslash (\): You cannot use backslashes in the URL.

- Colon (:): You cannot use alternate stream access.

- Percent sign (%): You cannot allow escaping after normalization.

- Ampersand (&): You cannot use multiple Common Gateway Interface (CGI)
  processes to run on a single request.

To resolve this issue, use one of the following methods:

- Describe this issue to users and explain that this issue limits OWA
  functionality even though it offers better security.

  -or-

- Edit the URLScan.ini file that is located in the
  <X>:\Winnt\System32\Inetsrv\Urlscan folder (where <X> is the
  drive in which you installed Windows) to allow these characters. If you do
  so, you allow potentially harmful commands to be used on the server that is
  running OWA, which may cause a security risk

For additional information about URLScan and Exchange Server, click the article
number below to view the article in the Microsoft Knowledge Base:

  Q309508 XCCC: IIS Lockdown and URLScan Configurations in an Exchange
  Environment


Additional query words:

======================================================================
Keywords          :  
Technology        : kbOutlookSearch kbOWASearch kbOWA550 kbOWA550SP1 kbOWA550SP2 kbOWA550SP3
Version           : :5.5
Issue type        : kbinfo

=============================================================================

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