C# Erro com windows form

[Arkcanjou]

Estou obtendo o seguinte erro quando tento adicionar um UserControl ao meu form principal

SettingsPanel.cs
 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace All_in_one
{
    public partial class SettingsPanel : UserControl
    {
        public SettingsPanel()
        {
            InitializeComponent();
        }
    }
}

 

SettingsPanel.design.cs

namespace All_in_one
{
    partial class SettingsPanel
    {
        /// <summary> 
        /// Variável de designer necessária.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary> 
        /// Limpar os recursos que estão sendo usados.
        /// </summary>
        /// <param name="disposing">true se for necessário descartar os recursos gerenciados; caso contrário, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Código gerado pelo Designer de Componentes

        /// <summary> 
        /// Método necessário para suporte ao Designer - não modifique 
        /// o conteúdo deste método com o editor de código.
        /// </summary>
        private void InitializeComponent()
        {
            this.showLastImg = new System.Windows.Forms.CheckBox();
            this.skipDuplicated = new System.Windows.Forms.CheckBox();
            this.downloadType = new System.Windows.Forms.ComboBox();
            this.SuspendLayout();
            // 
            // showLastImg
            // 
            this.showLastImg.AutoSize = true;
            this.showLastImg.Checked = true;
            this.showLastImg.CheckState = System.Windows.Forms.CheckState.Checked;
            this.showLastImg.Font = new System.Drawing.Font("Microsoft YaHei", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
            this.showLastImg.Location = new System.Drawing.Point(22, 3);
            this.showLastImg.Name = "showLastImg";
            this.showLastImg.Size = new System.Drawing.Size(254, 25);
            this.showLastImg.TabIndex = 0;
            this.showLastImg.Text = "Show last downloaded image";
            this.showLastImg.UseVisualStyleBackColor = true;
            // 
            // skipDuplicated
            // 
            this.skipDuplicated.AutoSize = true;
            this.skipDuplicated.Checked = true;
            this.skipDuplicated.CheckState = System.Windows.Forms.CheckState.Checked;
            this.skipDuplicated.Font = new System.Drawing.Font("Microsoft YaHei", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
            this.skipDuplicated.Location = new System.Drawing.Point(22, 34);
            this.skipDuplicated.Name = "skipDuplicated";
            this.skipDuplicated.Size = new System.Drawing.Size(187, 25);
            this.skipDuplicated.TabIndex = 1;
            this.skipDuplicated.Text = "Skip duplicated itens";
            this.skipDuplicated.UseVisualStyleBackColor = true;
            // 
            // downloadType
            // 
            this.downloadType.FormattingEnabled = true;
            this.downloadType.Items.AddRange(new object[] {
            "Images and Animated",
            "Images",
            "Animated"});
            this.downloadType.Location = new System.Drawing.Point(22, 65);
            this.downloadType.Name = "downloadType";
            this.downloadType.Size = new System.Drawing.Size(187, 23);
            this.downloadType.TabIndex = 2;
            // 
            // SettingsPanel
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.Controls.Add(this.downloadType);
            this.Controls.Add(this.skipDuplicated);
            this.Controls.Add(this.showLastImg);
            this.Name = "SettingsPanel";
            this.Size = new System.Drawing.Size(625, 354);
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        public CheckBox showLastImg;
        public CheckBox skipDuplicated;
        public ComboBox downloadType;
    }
}