The Module DLL kerbauth.dll failed to load. The data is the error. (The Module DLL C:Program FilesMicrosoftExchange ServerV14Binkerbauth.dll failed to load. The data is the error.)

Article
10/23/2013

I thought of writing this blog since i saw this issue on a few of cases.

Symptoms

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

After re-installing Exchange Server, you may see 503-Service unavailable while browsing Exchange Management Console or “Default Website”

At times, you may also see that the request keeps spinning in the browser and response does not comes back at all.

You may see following entry in the application event logs

The Module DLL E:\Program Files\Microsoft\Exchange Server\V14\Bin\kerbauth.dll failed to load. The data is the error.

Cause

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

Reason for 503-Service unavailable is that application pool is stopped but the actual reason is something else has caused the app pool crash and finally leading to stopped state. This application pool was stopped because of by default 5 consecutive exceptions within 5 minutes which is default behavior for IIS worker process.

This issue starts happening if during re-install of the Exchange Server, you select a different location to install.

When Exchange server was installed for the first time, it registers its custom modules with IIS and for this it makes entries in the IIS root config file i.e. applicationHost.config at this location C:\Windows\System32\inetsrv\config. These enties are made under the <globalmodules> section. You will see one such entry for kerbauth.dll.

While uninstalling the Exchange from the server, these entries might not be removed from the applicationHost.config. Issue starts when while re-installing the Exchange, the installation drive is changed. So such dlls will be copied at some other location while this entry is not modified in the applicationHost.config file.

While accessing the website, IIS will try to load this dll from the old path C:\Program Files\Microsoft\Exchange Server\V14\Bin\kerbauth.dll while this dll is not there and exists at some other path now.

While loading this dll, IIS will not be able to locate this and will throw an error and you must see an entry like following in the application event logs.

Log Name: Application

Source: Microsoft-Windows-IIS-W3SVC-WP

Date: 9/5/2013 11:03:23 AM

Event ID: 2280

Task Category: None

Level: Error

Keywords: Classic

User: N/A

Computer: STAL-EXCH01.stalber.loc

Description:

The Module DLL E:\Program Files\Microsoft\Exchange Server\V14\Bin\kerbauth.dll failed to load. The data is the error.

Event Xml:

<Channel>Application</Channel>

<Computer>STAL-EXCH01.stalber.loc</Computer>

</System>

<Data Name="ModuleDll">E:\Program Files\Microsoft\Exchange Server\V14\Bin\kerbauth.dll</Data>

</EventData>

</Event>

If IIS fails to load this dll, it keeps throwing this error message and then finally will stop the application pool. So we start getting 503-Service unavailable error.

Resolution

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

To resolve this issue, you need to manually change the path of kerbauth.dll to the latest path where exchange has been installed during reinstall.

1. Open ApplicationHost.config file at this path C:\Windows\System32\inetsrv\config

2. Find the entry for kerbauth.dll like following

<add name="kerbauth" image="E:\Program Files\Microsoft\Exchange Server\V14\Bin\kerbauth.dll" />

3. Change the path for this dll as per the latest location of the Exchange Server installation files.

Please feel free to provide the feedback on this post. Let me know if you have any concerns.

Comments

Anonymous
January 02, 2014
Thanks for help i has more than 2 weeks find solution for this issue. and with this procedure work for me. Best Regards
Anonymous
February 04, 2014
THANKS! Brilliant! In my case, I was re-using two 2012 Servers that previously ran Exchange 2010. I thought I removed all 2010 traces, but I guess not. This location was referring to "14" instead of "15" in the path.
Anonymous
April 09, 2014
Thanks for the article. This saved a lot of my time.
Anonymous
April 29, 2014
Thanks man! You just saved my life!
Anonymous
July 07, 2014
Similar problem but in reverse. I uninstalled Exchange Server 2010 from this server, rebooted, and left it for a couple of days to see if it threw up any errors. This error was coming up basically every second. I removed the entry to that file, reset IIS and all good. Thanks.
Anonymous
August 25, 2014
Can you just simply remove it? MS Exhange no longer exist..
Anonymous
August 26, 2014
Thanks for the feedback guys. I am happy that It helped. Mark, I apologize but I didn't get you. Thanks Gaurav
Anonymous
November 10, 2014
Thank you very much :) Solved my issues!
Anonymous
November 10, 2014
The comment has been removed
Anonymous
December 20, 2014
Similar problem, I uninstalled exchnage 20ao and changed the Drive letter of Exchange server path and re-installed the Exchange. Then I got this roblem.This error was coming up basically every second. I follwed this article and solved the issue. Thanks
Anonymous
February 06, 2015
Perfect solved my problem... no issues now.
Anonymous
February 19, 2015
The comment has been removed
Anonymous
March 30, 2015
excellent i was having couple of issues because of this WinRm issue, you saved my lot of time, it resolved almost all issue winch are related to remote connectivity for third-party installations even. thanks for the super blog..:)
Anonymous
May 17, 2015
@Thanks Austin, Sinisa, Arun, Mark, Nick, Ram, Kim, Harold, Naren Felling happy that it helped.
Anonymous
June 10, 2015
OMG! you are a genius. Thank you so muchhhhhhhhhhhhhhhhh
Anonymous
July 17, 2015
Gracias! me sirvio de guia para resolver mi problema.! Saludos.
Anonymous
August 09, 2015
Eduardo, Su bienvenida Thanks Mercedez
Anonymous
August 09, 2015
Thanks alot. It resolved the issue.
Anonymous
August 22, 2015
The comment has been removed
Anonymous
September 06, 2015
Superb information in this blog. I was facing the exact same issue, followed the steps exactly as you have listed but still unable to resolve the problem. Please tell me if I'm missing something here.
Anonymous
April 29, 2016
Superb! Resolution does the trick.Thx so much. Michael
Anonymous
April 30, 2016
Excellent post. To the point and solved my issue quickly.
Anonymous
May 03, 2016
Great thank you!
Anonymous
May 10, 2016
Thanks for the fix, I had a failed install and could not connect to the server via OWA or Powershell, couldn't uninstall due to mailboxes being present and not way to remove them. Noticed that the file kerbauth.dll was pointing to the wrong location. the fix work perfectly.
Anonymous
June 06, 2016
This solution fixed my issue for Exchange 2k16, Thanks a lot !!
Anonymous
July 22, 2016
Very helpful article, help out in my exchange 2016 live environment deployment
Anonymous
September 23, 2016
Tt worked, thanks for the info
- Anonymous
  November 19, 2016
  Welcome. Don't forget to rate it then. :)
Anonymous
November 30, 2016
GREAT! it worked for me, thank you!
Anonymous
September 23, 2017
Thanks a lot for this excellent article Gaurava!!

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