ClickOnce error message 'Access to the path 'C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config' is denied'

Question

Our ClickOnce application has been working fine. However, one of our users gets the following error:

+ Configuration system failed to initialize
+ An error occurred loading a configuration file: Access to the path 'C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config' is denied. (C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config)
+ Access to the path 'C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config' is denied.

Our Installation Folder URL appears to be fine as per the Stack Overflow article ClickOnce deployment error - access to the path is denied, and the discussion Access denied to machine.config on Win7 x64 isn't really clear what permissions should be checked, e.g. NETWORK SERVICE? And finally this MSDN article refers to changing passwords which doesn't make sense to me.

What might be causing the issue? And perhaps what permissions might be required?

Another Stack Overflow post, ClickOnce and configuration for a C# application, seems to refer to this issue, but asks a different question (trying to avoid using Machine.config).

Answer 1

We reinstalled .NET 4.5 on the user's machine and it now works fine.