ConfigurationErrorsException was unhandled while encrypting the connection string of the Web.config file

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C#

encryption

I tried to encrypt the connection string section of the web.config file via a simple winforms application.
I ran the VS2010 as an administrator and ran the following section of code.

private void encryptButton_Click(object sender, EventArgs e)
            {
    			Configuration config = GetConfiguration();
    			ConfigurationSection configSection = config.GetSection("connectionStrings");
                if (configSection != null)
    				// Only encrypt the section if it is not already protected
                    if (!configSection.SectionInformation.IsProtected)
    				{
                        configSection.SectionInformation.ProtectSection(
    						"DataProtectionConfigurationProvider");
                        configSection.SectionInformation.ForceSave = true;
    					config.Save();
    					DisplayWebConfig();
    				}
    		}

    private Configuration GetConfiguration() 
    		{
                var configFile = new FileInfo(@"C:\Users\abalawan\Desktop\CN\R13 new\Websites\ABC");
    			var vdm = new VirtualDirectoryMapping(configFile.DirectoryName,true,configFile.Name);
    			var wcfm = new WebConfigurationFileMap();
    			wcfm.VirtualDirectories.Add("/",vdm);
    			return WebConfigurationManager.OpenMappedWebConfiguration(wcfm, "/");
    		}

I tried to open the file from a physical path location and write back the encrypted info into it. But config.Save() threw me the below error.

ConfigurationErrorsException was unhandled.

Unable to save config to file 'C:\Users\abalawan\Desktop\CN\R13 new\Websites\ABC'.

Stacktrace looks like below :

at System.Configuration.Internal.WriteFileContext.ReplaceFile(String Source, String Target)
at System.Configuration.Internal.WriteFileContext.Complete(String filename, Boolean success)
at System.Configuration.Internal.InternalConfigHost.StaticWriteCompleted(String streamName, Boolean success, Object writeContext, Boolean assertPermissions)
at System.Configuration.Internal.InternalConfigHost.System.Configuration.Internal.IInternalConfigHost.WriteCompleted(String streamName, Boolean success, Object writeContext, Boolean assertPermissions)
at System.Configuration.Internal.InternalConfigHost.System.Configuration.Internal.IInternalConfigHost.WriteCompleted(String streamName, Boolean success, Object writeContext)
at System.Configuration.Internal.DelegatingConfigHost.WriteCompleted(String streamName, Boolean success, Object writeContext)
at System.Configuration.UpdateConfigHost.WriteCompleted(String streamName, Boolean success, Object writeContext)
at System.Configuration.MgmtConfigurationRecord.SaveAs(String filename, ConfigurationSaveMode saveMode, Boolean forceUpdateAll)
at System.Configuration.Configuration.SaveAsImpl(String filename, ConfigurationSaveMode saveMode, Boolean forceSaveAll)
at System.Configuration.Configuration.Save()
at EncryptionandDecryptionApplication.Form1.encryptButton_Click(Object sender, EventArgs e) in C:\Users\abalawan\Desktop\CN\EncryptionandDecryptionApplication\EncryptionandDecryptionApplication\Form1.cs:line 55
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(Form mainForm)
at EncryptionandDecryptionApplication.Program.Main() in C:\Users\abalawan\Desktop\CN\EncryptionandDecryptionApplication\EncryptionandDecryptionApplication\Program.cs:line 18
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()

Please help me through . Thanks in advance.