It sounds like you're copying the script into a WF 10.2 installation and have mismatched references? Can you post a screenshot of the script editor or the full contents of the script so we can see where the mismatch is?

He're the script:

namespace WorkflowActivity.Scripting.ScriptparaexportardocumentosfueradeLaserfiche
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Data.SqlClient;
    using System.Text;
    using Laserfiche.DocumentServices;
    using Laserfiche.RepositoryAccess;
    using Laserfiche.Workflow.Activities;
    using Laserfiche.SecurityTokenService;
    using Laserfiche.UI;
    using System.IO;
    using LFSO90Lib;
    using System.Xml.Serialization;
    using System.Xml;
    using System.Text.RegularExpressions;
    using System.Xml.Linq;

    /// <summary>
    /// Provides one or more methods that can be run when the workflow scripting activity is performed.
    /// </summary>
    public class Script1 : RAScriptClass91 //RAScriptClass102
    {
        /// <summary>
        /// This method is run when the activity is performed.
        /// </summary>
        protected override void Execute()
        {
            string valor = "";
            string campo = "";
            string paso = "0";
            string _c = "";
            string _v = "";
            string NoExpediente = "";
            string Clasificacion = "";
            string rutabase = "C:\\Users\\rcairo\\Box Sync\\Conciliaciones PGS KHR DWT\\4. FACTURAS PGS KHR\\";

            try
            {
                DocumentInfo DI = (DocumentInfo)this.BoundEntryInfo;
                EntryInfo entry = Entry.GetEntryInfo(DI.Id, RASession);
                var fvc = entry.GetFieldValues();

                PageInfo pgInfo = DI.GetPageInfo(1);
                DocumentStatistics docStats = DI.GetStatistics();

                string volumeName = DI.VolumeName;
                string pagePath = pgInfo.ImageFilePath;
                string edocPath = docStats.ElecDocumentPath;

                //CREAR FOLDER PRINCIPAL
                string folderLocation = rutabase;
                bool exists = System.IO.Directory.Exists(folderLocation);
                if (!exists)
                {
                    System.IO.Directory.CreateDirectory(folderLocation);
                }

                string p = DI.Path.Split('\\')[4] + "\\" + DI.Path.Split('\\')[5] + "\\" + DI.Path.Split('\\')[6] + "\\" + DI.Path.Split('\\')[7].Split('/')[0];

                string filePath = @"C:\temp\Error.txt";
                using (StreamWriter writer = new StreamWriter(filePath, true))
                {
                    writer.WriteLine("Mensaje :" +  p.Trim());
                }

                //CREAR FOLDER PARA DOCUMENTOS
                string folderExpedienteLocation =  rutabase + p + "\\";
                bool existsNoExp = System.IO.Directory.Exists(folderExpedienteLocation);
                if (!existsNoExp)
                {
                    System.IO.Directory.CreateDirectory(folderExpedienteLocation);
                }

                DI.Lock(LockType.Exclusive);

                DocumentExporter dExp = new DocumentExporter();
                dExp.CompressionQuality = 50;
                dExp.IncludeAnnotations = true;
                dExp.BlackoutRedactions = true;
                dExp.PageFormat = DocumentPageFormat.Jpeg;

                var ExportOptions = PdfExportOptions.RenderAnnotationsAsImage | PdfExportOptions.IncludeText;

                string path = folderExpedienteLocation;
                string filename = DI.Name + ".pdf";

                dExp.ExportPdf(DI, DI.AllPages, ExportOptions, path + filename);

                DI.Unlock();
                DI.Dispose();

            }
            catch(Exception ex){
                string filePath = @"C:\temp\Error.txt";
                using (StreamWriter writer = new StreamWriter(filePath, true))
                {
                    writer.WriteLine("Mensaje :" + paso + Environment.NewLine + campo + ":" + valor + Environment.NewLine +  ex.Message  + "<br/>" + Environment.NewLine + "StackTrace :" + ex.StackTrace +
                    "" + Environment.NewLine + "Fecha :" + DateTime.Now.ToString());
                    writer.WriteLine(Environment.NewLine + "-----------------------------------------------------------------------------" + Environment.NewLine);
                }
            }

        }

        //use System.Text.RegularExpressions before using this function
        public bool vldRegex(string strInput)
        {
        //create Regular Expression Match pattern object
        Regex myRegex = new Regex("/[0-9A-Fa-f]{6}/g");
        //boolean variable to hold the status
        bool isValid = false;
        if (string.IsNullOrEmpty(strInput))
        {
        isValid = false;
        }
        else
        {
        isValid = myRegex.IsMatch(strInput);
        }
        //return the results
        return isValid;
        }

    }

    public class MetaData
    {
         public string Campo {get; set;}
         public string Valor {get; set;}
    }

}