Mixed mode assembly is built against version 'v2.0.50727' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.

<configuration>
  <startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0"/>
  </startup>
</configuration>

[DllImport("mscoree.dll", CharSet=CharSet.Unicode)]
public static extern bool StrongNameSignatureVerificationEx(string wszFilePath, bool fForceVerification, ref bool pfWasVerified);

using System;
using System.Reflection;
using System.Runtime.InteropServices;

namespace SigCheck
{
   public class Validation
   {
       [DllImport("mscoree.dll", CharSet = CharSet.Unicode)]
       public static extern bool StrongNameSignatureVerificationEx(
           string wszFilePath, bool fForceVerification, ref bool pfWasVerified);

       public static void SigCheck()
       {
           var assembly = Assembly.GetExecutingAssembly();
           bool pfWasVerified = false;
           if (!StrongNameSignatureVerificationEx(assembly.Location, true, ref pfWasVerified))
           {
               //خاتمه برنامه در صورت عدم وجود امضای دیجیتال معتبر
               throw new Exception();
           }
       }
   }

   class Program
   {
       static void Main(string[] args)
       {
           Validation.SigCheck();
       }
   }
}

foreach (Assembly currentassembly in AppDomain.CurrentDomain.GetAssemblies()) 
{
   Type t = currentassembly.GetType("typeName", false, true);
    if (t != null) {return currentassembly.FullName;}
}

using System;
using System.Diagnostics;
using Microsoft.Office.Tools.Word;
using Action = Microsoft.Office.Tools.Word.Action;

       private SmartTag _st;
       private void init()
       {
           try
           {
               //Enable Smart Tags in Word
               if (!Application.Options.LabelSmartTags)
               {
                   //ممکن است اسمارت تگ‌ها در ورد غیرفعال باشند. به این صورت می‌شود آنها را فعال کرد
                   Application.Options.LabelSmartTags = true;
               }

               _st = new SmartTag(@"www.microsoft.com/Demo#FarsiSmartTag", @"فارسی به پارسی");

               //دریافت واژه‌های فارسی از دیتابیس و افزودن خودکار آنها به اسمارت تگ‌ها
               if (!DBhelper.AddSmartTagItems(_st, "select distinct farsi from tblFarsiToParsi")) return;

               Action stActions = new Action("تبدیل");//تعریف یک اکشن جدید
               stActions.Click += stActions_Click;//انتساب روال‌های رخداد گردان
               stActions.BeforeCaptionShow += stActions_BeforeCaptionShow;
               _st.Actions = new[] { stActions };
               VstoSmartTags.Add(_st);//افزودن اسمارت تگ به مجموعه
           }
           catch (Exception ex)
           {
               EventLog.WriteEntry("FarsiToParsi", ex.ToString(), EventLogEntryType.Error, 7);
           }
       }

       private void ThisAddIn_Startup(object sender, EventArgs e)
       {
           init();
       }

       static void stActions_BeforeCaptionShow(object sender, ActionEventArgs e)
       {
           try
           {
               Action clickedAction = sender as Action;
               if (clickedAction != null)
               {
                   string parsi = DBhelper.FindParsi(e.Text);//معادل پارسی از دیتابیس دریافت می‌شود
                   clickedAction.Caption = (parsi == string.Empty ? e.Text : parsi);
               }
           }
           catch (Exception ex)
           {
               EventLog.WriteEntry("FarsiToParsi", ex.ToString(), EventLogEntryType.Error, 7);
           }
       }

       static void stActions_Click(object sender, ActionEventArgs e)
       {
           try
           {
               Action clickedAction = sender as Action;
               if (clickedAction != null)
               {
                   e.Range.Text = clickedAction.Caption;//جایگزینی متن موجود با عنوانی که پیشتر پارسی شده است
               }
           }
           catch (Exception ex)
           {
               EventLog.WriteEntry("FarsiToParsi", ex.ToString(), EventLogEntryType.Error, 7);
           }
       }

using System;
using System.Data.SQLite;
using System.Diagnostics;
using System.Reflection;
using Microsoft.Office.Tools.Word;

namespace Farsi2Parsi
{
   class DBhelper
   {
       #region Methods (2)

       // Public Methods (2)

       public static bool AddSmartTagItems(SmartTag st, string strSQL)
       {
           SQLiteDataReader myReader = null;
           SQLiteCommand sqlCmd = null;
           bool ret = false;
           try
           {
               SQLiteConnection sqlCon = new SQLiteConnection
               {
                   ConnectionString = "Data Source=" + ConStr.ConnectionString
               };
               sqlCon.Open();
               sqlCmd = new SQLiteCommand(strSQL, sqlCon);
               myReader = sqlCmd.ExecuteReader();

               if (myReader != null)
                   while (myReader.Read())
                   {
                       if (myReader.GetValue(0) != DBNull.Value)
                           st.Terms.Add(myReader.GetValue(0).ToString());
                   }

               ret = true;
           }
           catch (Exception ex)
           {
               EventLog.WriteEntry("FarsiToParsi", ex + "\n" + Environment.CurrentDirectory + "\n" +
               Assembly.GetExecutingAssembly().Location, EventLogEntryType.Error, 7);
           }
           finally
           {
               if (myReader != null)
                   myReader.Close();

               if (sqlCmd != null)
                   sqlCmd.Connection.Close();
           }
           return ret;
       }

       public static string FindParsi(string farsi)
       {
           SQLiteDataReader myReader = null;
           SQLiteCommand sqlCmd = null;
           string ret = string.Empty;
           string strSQL = "select parsi from tblFarsiToParsi where farsi='" + farsi.Replace("'", "''") + "'";
           try
           {
               SQLiteConnection sqlCon = new SQLiteConnection
               {
                   ConnectionString = "Data Source=" + ConStr.ConnectionString
               };
               sqlCon.Open();
               sqlCmd = new SQLiteCommand(strSQL, sqlCon);
               myReader = sqlCmd.ExecuteReader();

               if (myReader != null)
               {
                   myReader.Read(); //اولین مورد کافی است
                   if (myReader.GetValue(0) != DBNull.Value)
                       ret = myReader.GetValue(0).ToString();
               }
           }
           catch (Exception ex)
           {
               EventLog.WriteEntry("FarsiToParsi", ex + "\n" + Environment.CurrentDirectory + "\n" +
               Assembly.GetExecutingAssembly().Location, EventLogEntryType.Error, 8);
           }
           finally
           {
               if (myReader != null)
                   myReader.Close();

               if (sqlCmd != null)
                   sqlCmd.Connection.Close();
           }
           return ret;
       }
       #endregion Methods
   }
}

   class ConStr
   {
       public static string ConnectionString
       {
           get
           {
               return Microsoft.Win32.Registry.LocalMachine.OpenSubKey("SOFTWARE\\FarsiToParsi").GetValue("folder") + "\\ErrorsBank.sqlite";
           }
       }
   }