Error 'Microsoft.CSharp.RuntimeBinder.RuntimeBinderException' in System.Core.dll

I'm trying to debug a C # application and are experiencing this error:

Exception thrown: 'Microsoft.CSharp.RuntimeBinder.RuntimeBinderException' in Microsoft.CSharp.dll
'Emulador AFO.vshost.exe' (CLR v4.0.30319: Emulador AFO.vshost.exe): Loaded 'Anonymously Hosted DynamicMethods Assembly'. 
Exception thrown: 'Microsoft.CSharp.RuntimeBinder.RuntimeBinderException' in System.Core.dll

Part of the code that is displaying the error:

public EnvironmentForm()
{
    InitializeComponent();
    LoadingForm lForm = new LoadingForm();
    if (lForm.ShowDialog().ToString() != null)
    {
        #region <Show EnvironmentForm>
        this.SizeGripStyle = SizeGripStyle.Show;
        this.ShowIcon = true;
        this.ShowInTaskbar = true;
        this.WindowState = FormWindowState.Normal;
        #endregion
        ConnectedUsers = this.lbl_ConnectedUsers;
        Library.F.UpgradeConnectedUsersEvent();
        DB.m_Logger = new Logger(this.rBox_Logger);
        DB.CanLogger = this.cBox_Logger.Checked;
        SetIpDoor();
        return;
    }
    else Environment.Exit(0);
}

Does anyone know what it can be?