System.ArgumentException

The exception that is thrown when one of the arguments provided to a method is not valid.

Minimum version: >= 1.1 >= Core 1.0

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How to handle it

try
{

}
catch (System.ArgumentException e)
{

}

try
{

}
catch (System.ArgumentException e) when (e.Message.Contains("something"))
{

}

try
{

}
catch (System.ArgumentException e) when (LogException(e))
{

}

private static bool LogException(Exception e)
{
    logger.LogError(...);
    return false;
}

How to avoid it

We haven't written anything about avoiding this exception yet. Got a good tip on how to avoid throwing System.ArgumentException? Feel free to reach out through the support widget in the lower right corner with your suggestions.

YouTube videos

C# : System.ArgumentException: Parameter is not valid

MVC How to fix error Keyword not supported metadata

System Argument Exception Keyword not supported

System.ArgumentException:'Format of the initialization string does not conform to s...............

Possible fixes from StackOverflow

Just a guess what does the variable json contain after

var json = Sys.Serialization.JavaScriptSerializer.serialize(obj);?

If it is a valid json object like {"foo":"foovalue", "bar":"barvalue"} then jQuery might not send it as json data but instead serialize it to foor=foovalue&bar=barvalue thus you get the error "Invalid JSON primitive: foo"

Try instead setting the data as string

$.ajax({
    ...
    data: '{"foo":"foovalue", "bar":"barvalue"}', //note the additional quotation marks
    ...
})

This way jQuery should leave the data alone and send the string as is to the server which should allow ASP.NET to parse the json server side.

I solved this problem by resetting the user data

devenv.exe /resetuserdata

and remove the ".vs" folder in my project.

WARNING: this will reset all your user settings. Essentially, it is like resetting to factory defaults. You will lose any custom keyboard shortcuts, extensions you've installed etc.

it's working something like this

data: JSON.stringify({'id':x}),

Complete worked example for WPF + MVVM.

Tested on MSVC 2017.

In the view:

<TextBlock Text="Some text to be colored by an enum">
    <TextBlock.Style>
        <Style TargetType="{x:Type TextBlock}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding StatusIcon}" Value="{x:Static my:StatusIcon.Warning}">
                    <Setter Property="Foreground" Value="Yellow"/>
                </DataTrigger>
                <DataTrigger Binding="{Binding StatusIcon}" Value="{x:Static my:StatusIcon.Error}">
                    <Setter Property="Foreground" Value="Red}"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </TextBlock.Style>
</TextBlock>

If using ReSharper, and if the DataContext is set up properly, there will be intellisense when you hit the . after StatusIcon, i.e. it will show the properties of the enum which are Debug, Info, Warning or Error.

If using ReSharper, it will suggest the following update to the namespace in the header for the XAML file(its good like that):

xmlns:my="clr-namespace:Class.Path.MyViewModel;assembly=MyAssembly"

And the VieModel:

public enum StatusIcon
{
    Debug,
    Info,
    Warning,
    Error
}

public class MyViewModel
{
    public StatusIcon StatusIcon { get; }
}

We also use Fody for automated binding.

I had the same problem. I googled it for two days. At last I accidentally noticed that the problem was access modifier of the constructor of the Controller. I didn’t put the public key word behind the Controller’s constructor.

public class MyController : ApiController
    {
        private readonly IMyClass _myClass;

        public MyController(IMyClass myClass)
        {
            _myClass = myClass;
        }
    }

I add this experience as another answer maybe someone else made a similar mistake.