SCCM - WSUS - HTTP Error 500.19 - 0x8007007e

Problem: 

Install WSUS on Server

The WSUSsetup.log (c:\username\AppData\Local\Temp\WSUSSetup.log) suggests everything has installed successfully…..

….however, WSUS kicks out a Connection Error when it opens (hitting ‘Reset Server Node’ doesn’t help much).

Since WSUS relies on IIS, you check the IIS landing page on the local host; http://localhost/, unfortunately returns the following error:

HTTP Error 500.19 - Internal Server Error 
The requested page cannot be accessed because the related configuration data for the page is invalid. Module DynamicCompressionModule 
Notification SendResponse 
Handler StaticFile 
Error Code 0x8007007e 
Requested URL http://localhost:80/ 
Physical Path C:\inetpub\wwwroot 
Logon Method Anonymous 
Logon User Anonymous

Cause:

The error Code 0x8007007e translates as ERROR_MOD_NOT_FOUND (i.e. The specified ‘DynamicCompressionModule’ could not be found).

When WSUS is installed, it adds the XPress compression scheme module (suscomp.dll) into IIS. In IIS, Compression Schemes are defined globally and so will attempt to load in every application Pool within IIS. As such, it will kick out this error when the 64bit version of suscomp.dll attempts to load in an application pool which is running in 32bit mode.

This module entry looks like:

<scheme name="xpress" doStaticCompression="false" doDynamicCompression="true" 
dll="C:\Windows\system32\inetsrv\suscomp.dll" staticCompressionLevel="10" 
dynamicCompressionLevel="0" />

Fix:

Disable the XPress compression scheme that was introduced by WSUS from the configuration using the command below:

%windir%\system32\inetsrv\appcmd.exe set config -section:system.webServer/httpCompression /-[name='xpress']

After you have run the command you should find that the IIS landing page appears as expected and that the WSUS console opens correctly:

Sidenote: To re-enable this compression scheme use the following command: 

%windir%\system32\inetsrv\appcmd.exe set config -section:system.webServer/httpCompression /+[name='xpress',doStaticCompression='false',dll='%windir%\system32\inetsrv\suscomp.dll']