ConfigurationManager.GetSection Gives Error "Could not load type....from assembly..."

Question

My app.config file is as follows:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <section name="ProcessConfiguration" type="Configuration.ProcessConfigurationSection, Configuration" />
    </configSections>
    <ProcessConfiguration>
        <processes>
            <process name="Process1" />
        </processes>
    </ProcessConfiguration>
</configuration>

I have the following (separate) classes to get the configuration:

namespace Configuration
{
    using System.Configuration;

    public class ProcessesConfigurationSection : ConfigurationSection
    {
        [ConfigurationProperty("processes", IsDefaultCollection = false)]
        [ConfigurationCollection(typeof(ProcessCollection))]
        public ProcessCollection Processes
        {
            get
            {
                return (ProcessCollection)base["processes"];
            }
        }
    }
}

namespace Configuration
{
    using System.Configuration;

    public class ProcessCollection : ConfigurationElementCollection
    {
        public ProcessConfig this[int index]
        {
            get
            {
                return (ProcessConfig)BaseGet(index);
            }

            set
            {
                BaseAdd(index, value);
            }
        }

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

        protected override ConfigurationElement CreateNewElement()
        {
            return new ProcessConfig();
        }
    }
}

namespace Configuration
{
    using System.Configuration;

    public class ProcessConfig : ConfigurationElement
    {
        [ConfigurationProperty("name", IsRequired = true, IsKey = true)]
        public string Name 
        {
            get
            {
                return (string)this["name"];
            }
            set
            {
                this["name"] = value;
            }
        }
    }
}

However when I hit this line of code:

var processConfigurationSection = ConfigurationManager.GetSection("ProcessConfiguration") as ProcessesConfigurationSection;

I get the error which states:

An error occurred creating the configuration section handler for ProcessConfiguration: Could not load type 'Configuration.ProcessConfigurationSection' from assembly 'Configuration'.

I'm completely stumped, if anyone can help me out I'd really appreciate it.

Answer 1

In the line:

<section name="ProcessConfiguration" type="Configuration.ProcessConfigurationSection, Configuration" />

The name 'Configuration' should refer to the DLL that you re building, please try checking this and correct if needed.

Also I think you may have a typo, in your code the type name is:

ProcessesConfigurationSection

(Note the Processes vs Process)

Answer 2

This error has been raised because the invoking assembly couldn't load the class type in the specified assembly. This error can be caused by a space after the type name (which has happened to me), for example the following config section

type="Configuration.ProcessConfigurationSection , Configuration"

will generate this error too.