How to: Remove error “Error 503 – Service Unavailable” after removing Exchange Server 2013 on IIS

How to: Remove error “Error 503 – Service Unavailable” after removing Exchange Server 2013 on IIS

Okay, so I am guilty of many bad practices like not backing up a RAID array before expanding it, and as of late, using a server box that had Exchange Server 2013 for other purposes instead of reinstalling. To my defense, Microsoft’s automatic key activation is a pain, as I am reinstalling a server and they count that against my server quota and then if I reinstall too much too often I need to give them a call to activate… so I decided simply uninstalling Exchange 2013 would suffice… no comment. My recommendation and best practice is to wipe that server clean and repurpose it.

Anyway, getting back on track if you uninstalled Exchange 2013, installed a bunch of other things and now you are enjoying a bunch of left over Exchange goodies like this “Error 503 – Service Unavailable” in IIS, welcome to my world.

The Cause

You installed Exchange 2013, and when removed it doesn’t do a good clean up job. As you can see in IIS there are a bunch of app pools from your server’s Exchange days and the inner configs of IIS are also full of them. The issue on this particular problem is the following which you can observe on your Event Viewer:

Log Name:      Application
Source:        Microsoft-Windows-IIS-W3SVC-WP
Date:          09/03/2013 03:55:23 p. m.
Event ID:      2280
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      SomeServerName
Description:
The Module DLL C:Program FilesMicrosoftExchange ServerV15Binkerbauth.dll failed to load.  The data is the error.
Event Xml:
xmlns=”http://schemas.microsoft.com/win/2004/08/events/event“>
<System>
<Provider Name=”Microsoft-Windows-IIS-W3SVC-WP” Guid=”{670080D9-742A-4187-8D16-41143D1290BD}” EventSourceName=”W3SVC-WP” />
<EventID Qualifiers=”49152″>2280
<Version>0</Version>
<Level>2</Level>
<Task>0</Task>
<Opcode>0</Opcode>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime=”2013-03-09T21:55:23.000000000Z” />
<EventRecordID>41566</EventRecordID>
<Correlation />
<Execution ProcessID=”0″ ThreadID=”0″ />
<Channel>Application</Channel>
<Computer>SomeComputerNAme</Computer>
<Security />
</System>
<EventData>
C:Program FilesMicrosoftExchange ServerV15Binkerbauth.dll
<Binary>7E000000</Binary>
</EventData>
</Event>

The solution:

Take a look at: C:WindowsSystem32inetsrvconfigapplicationHost.config there you will find a line that reads like so:

<add name=”kerbauth” image=”C:Exchange ServerV15Binkerbauth.dll” />

At this point if you stop IIS, edit the file as an administrator and remove that line your problem will be solved. A word of caution to this tale, if you keep exploring the file you will see that Exchange references are all over the place and probably you will need to add a Kerberos Authentication DLL to replace that entry if you have an application that has been set up to use Kerberos. My advice: IF you can use another server and wipe this one clean… I have no clue what other issues you may encounter because of the poorly uninstalled Exchange Server.

Rumor has it this happens on Exchange Server 2010 as well…