Troubleshooting .NET Framework parser error after upgrade to Windows 8

After upgrading from Windows 7 Ultimate to Windows 8 Pro, I encountered buggy behavior of several of applications based on .NET Framework 2.0/3.5. Apparently, the error manifested itself in a way that the apps didn’t want to run properly and were failing with error “Error parsing C:\Windows\Microsoft.NET\Framework\v2.0.50727\Config\machine.config. Parser returned error 0xC00CE556”. I didn’t paying attention on this until it happened when I tried to install Visual Studio 2012 – installer simply wouldn’t start.

Wisdom of internet didn’t give me proper answer, nor I couldn’t find any answer on Microsoft Answers website. Some of things I tried were:

  • Using sfc / scannnow

  • Changing machine.config permissions

So, in the end I found this blog post that is explaining the troubleshooting of the error. Procedure is as follows:

  1. Rename machine.config to machine.config. old

  2. Copy machine.config.default and rename the copy to machine.config

and afterwards everything works. You need to confirm the rename, because this is system-related folder and you will have UAC prompt asking you for confirmation.

I was sure that I resolved the issue, and I was very happy with that, so I started installing Visual Studio 2012 on my machine. But, installer would simply fail after installing several packages with message “Fatal error during installation”. After several tries, I found the same error buried in the install log, but with path to x64 machine.config. I repeated the procedure, and the install succeeded.

I hope that this blog post will help you resolve the issue, but you can also visit source of this wisdom

Until next time