HTTP Error 503 while opening the Management console

Products

• Client Management Suite
• IT Management Suite

Issue/Introduction

Unable to access the Symantec Management Platform (SMP) Console and the following error is received when trying to open the SMP Console:

HTTP Error 503. The service is unavailable.

The following error is also seen when trying to open IIS manager:

Environment

ITMS 8.x

Cause

The applicationHost.config ( C:\Windows\System32\inetsrv\config\ ) is corrupted and shows file size 0 KB.

Note: Sometimes, the IIS service doesn't start if the applicationHost.config files gets corrupted and it gives the above error while accessing smp websites and application pool.

Resolution

• Navigate to "C:\inetpub\history" directory. You will find the history of all the applicationHost.config files in this directory.
• Use one of the latest applicationHost.config file from this directory that you know is not corrupted. 
• You need to copy this applicationHost.config file and paste it into the "C:\Windows\system32\inetsrv\config" directory to replace the corrupted file.
• Restart the IIS service.