Error while importing and exporting Excel sheet

System.Data.OleDb.OleDbException (0x80004005): External table is not in the expected format. at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection) at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions) at System.Data.ProviderBase.DbConnectionInternal.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.OleDb.OleDbConnection.Open() at iqmsampleworks_project.Areas.admin.Controllers.adminController.import(HttpPostedFileBase file, HttpPostedFileBase file1) in f:\Final\IQM SAMPLE WORK - Copy\Areas\admin\Controllers\adminController.cs:line 84

public ActionResult import(HttpPostedFileBase file, HttpPostedFileBase file1)
{
    try
    {
   


        if (file1 != null)
        {
            file1.SaveAs(HttpContext.Server.MapPath("~/File/") + file1.FileName);

        }
        
       
        if (file != null)
        {
            string path = string.Concat(Server.MapPath("~/File3/" + file.FileName));
            if (System.IO.File.Exists(path))
            {
                System.IO.File.Delete(path);
             
            }
            
            file.SaveAs(path);
            //ViewData["Test"] = path;
            // Connection String to Excel Workbook
            string excelConnectionString = string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=Excel 8.0", path);
            OleDbConnection connection = new OleDbConnection();
            connection.ConnectionString = excelConnectionString;
            OleDbCommand command = new OleDbCommand("select * from [file.FileName]", connection);
            connection.Open();
            DataTable dt = new DataTable();

            dt = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
            if (dt == null)
            {
                return null;
            }

            String[] excelSheets = new String[dt.Rows.Count];
            int t = 0;
           
            foreach (DataRow row in dt.Rows)
            {
                excelSheets[t] = row["TABLE_NAME"].ToString();
                t++;
            }
            
            DataSet ds = new DataSet();
            string query = string.Format("Select * from [{0}]", excelSheets[0]);
            using (OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, connection))
            {
                dataAdapter.Fill(ds);
            }
            for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
            {

                ConfigurationTable model = new ConfigurationTable();
                string b = ds.Tables[0].Rows[i]["ID"].ToString();
                int c = Convert.ToInt16(b);
                int cnt = db.ConfigurationTables.Where(a => a.ID == c).Count();
                if (cnt == 1)
                {

                    ConfigurationTable model1 = db.ConfigurationTables.SingleOrDefault(e => e.ID == c);
                    model1.ID = Convert.ToInt16(ds.Tables[0].Rows[i]["ID"].ToString());
                    model1.DomainName = ds.Tables[0].Rows[i]["DomainName"].ToString();
                    model1.Type = ds.Tables[0].Rows[i]["Type"].ToString();
                    model1.Category = ds.Tables[0].Rows[i]["Category"].ToString();
                    model1.SampleName = ds.Tables[0].Rows[i]["SampleName"].ToString();
                    model1.DevelopedBy = ds.Tables[0].Rows[i]["DevelopedBy"].ToString();
                    model1.url = ds.Tables[0].Rows[i]["url"].ToString();
                    model1.UserType = ds.Tables[0].Rows[i]["UserType"].ToString();
                    model1.UserType1 = ds.Tables[0].Rows[i]["UserType1"].ToString();
                    model1.UserType2 = ds.Tables[0].Rows[i]["UserType2"].ToString();
                    model1.UserType3 = ds.Tables[0].Rows[i]["UserType3"].ToString();
                    model1.UserType4 = ds.Tables[0].Rows[i]["UserType4"].ToString();
                    model1.UserType5 = ds.Tables[0].Rows[i]["UserType5"].ToString();
                    model1.UserType6 = ds.Tables[0].Rows[i]["UserType6"].ToString();
                    model1.U