Exchange OWA not working and WAS Error 5172

Microsoft Exchange

Recently I came across an error where OWA had stopped working on an Exchange 2010 server.

After a quick look in services I could see that the IIS Admin Service wasn’t running. So I tried a quick iisreset /restart command, but received the following error.

iisreset error

Back to Services again, and I could see that the World Wide Web Publishing Service wasn’t started. I tried to start the service but it failed to start.

So i took a look at its dependencies and noticed the Windows Process Activation Service wasn’t started either.World Wide Web Publish Service Dependencies

I tried starting the Windows Process Activation Service, but it wouldn’t start and produced the following error message:

The Windows Process Activation Service terminated with the following error:
The data is invalid.

So I had a quick check in the event logs, and each time the Windows Process Activation Service tried to start it generated an Event ID 5172 Error message in the System Event log:

The Windows Process Activation Service encountered an error trying to read the configuration data from file ‘C:Windowssystem32intsrvschemaNetFx40_IS_schema_update.xml’, line number ‘1’. The error message is: ‘Configuration file is not well-formed XML’. The data field contains the error number.

Event ID 5172 Error WASSo I browsed to the folder in question to take a look at the xml file and found the following.

The file size was 0 KB which and contained no data. On further investigation I had a quick look at the Windows update history and the issue occurred after Microsoft.Net Framework 4.5.2 for Windows Server 2008 R2 x64-based Systems (KB2901983) was installed.

Windows Update History

Whenever a change is made in IIS a backup of the configuration is saved in the C:\inetpub\history folder.  So I browsed to the last CFGHISTORY folder to take a look, and sure enough the NetFx40_IIS_schema_update.xml file was 4 KB in size.

I copied  the NetFx40_IIS_schema_update.xml file from the C:inetpubhistory folder to the C:\Windows\System32\inetsrv\config\schema folder.

I was then able to run iisreset, at which point the WAS, World Wide Publishing and IIS Admin Services all started sucessfully.



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2 thoughts on “Exchange OWA not working and WAS Error 5172

  1. Rob

    This post just saved me and put an end to days of troubleshooting. While my issue wasn’t related to Exchange, it definitely solved my problem.

    Thank you for posting it!


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