The config system was unable to initialize error while loading custom section from app.config

I have defined a config section in my app.config like this:

    <?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="RegisterCompanies"
             type="ConfigTest.RegisterCompaniesConfig, ConfigTest" 
             allowLocation="true" 
             allowDefinition="Everywhere"/>
          </configSections>      
  <RegisterCompanies>
    <Companies>
      <Company name="Tata Motors" code="Tata"/>
      <Company name="Honda Motors" code="Honda"/>
    </Companies>
  </RegisterCompanies>      
      </configuration>

      

        
        
        
      

    

To read this information, I created three classes this way: RegisterCompaniesConfig class

public class RegisterCompaniesConfig : ConfigurationSection
    {
        public static RegisterCompaniesConfig GetConfig() 
        {
            string path = Path.Combine(Application.StartupPath, "ConfigTest.exe.config");
            Configuration config = System.Configuration.ConfigurationManager.OpenExeConfiguration(path);
            RegisterCompaniesConfig serviceSection = ConfigurationManager.GetSection("RegisterCompanies") as RegisterCompaniesConfig;
            return serviceSection;
            //return (RegisterCompaniesConfig)System.Configuration.ConfigurationManager.GetSection("RegisterCompanies");
        }

        [System.Configuration.ConfigurationProperty("Companies")]
        public Companies Companies 
        {
            get
            {
                object o = this["Companies"]; return o as Companies;
            }
        }
    }

      

        
        
        
      

    

then the class of companies:

public class Companies : ConfigurationElementCollection
    {
       [System.Configuration.ConfigurationProperty("Company")]
        public Company this[int index] 
        {
            get
            {
                return base.BaseGet(index) as Company;
            } 
            set 
            { 
                if (base.BaseGet(index) != null)
                { base.BaseRemoveAt(index); } this.BaseAdd(index, value);
            }
        }
        protected override ConfigurationElement CreateNewElement()
        {
            return new Company();
        }

        protected override object GetElementKey(ConfigurationElement element)
        {            
            return ((Company)element).Name;
        }
    }

      

        
        
        
      

    

and the last one is the company class:

public class Company : ConfigurationElement
    {
        [ConfigurationProperty("name", IsRequired = true)]
        public string Name 
        {
            get 
            {
                return this["name"] as string; 
            } 
        }
        [ConfigurationProperty("code", IsRequired = true)]
        public string Code
        {
            get
            {
                return this["code"] as string; 
            } 
        }
    }

      

        
        
        
      

    

after that when i want to execute the section by calling the following method

var config = RegisterCompaniesConfig.GetConfig();

      

        
        
        
      

    

I am getting the error: Failed to initialize the config system Please someone look at this above code where the problem is, it looks, everything is good for me ....