'machine.config' is denied

My application is running on windows server 2000 and IIS 6. Up until this morning the application was working fine. But now I'm getting the error below:

Configuration Error 
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately. 

Parser Error Message: An error occurred loading a configuration file: Access to the path 'C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Config\machine.config' is denied.

Source Error: 


[No relevant source lines]


Source File: C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Config\machine.config    Line: 0 


--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.272

Does anyone know what's going on?



Solution 1:[1]

Check that the account which the application pool is running under has access to

'C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Config\machine.config'

The permissions may have changed if the user account was updated or .NET was updated

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 benni_mac_b