Unable to retrieve data in unit testing

I have a question about retrieving data, which is something I am trying to learn and also first time to used it.

Error for test failed: "Test method TestBusinessLogic.MediaDurationBLTest.OpenModelTest threw exception: System.Exception: Unable to retrieve Media Duration Model Another user has already updated the model. Please refresh and try again."

MediaDurationBLTest.cs

This is the main method:

  [TestMethod()]
        public void OpenModelTest()
        {
            MediaDurationDS mds = new MediaDurationDS();
            PopulateTestDataSet(mds);

            MediaDurationBL target = new MediaDurationBL();
            TestBusinessLogic.BusinessLogic_MediaDurationBLAccessor accessor = new TestBusinessLogic.BusinessLogic_MediaDurationBLAccessor(target);
            //assign accessor to mds
            accessor.mMediaDurationDataSet = mds;

            int modelID = 5514;

            target.OpenModel(modelID);

            Assert.AreEqual(20, mds.Tables.Count, "# of tables retrieved are different");

            //We are creating copy of ProjectMetricData, check if copyTable and original table are same
            //except projectmetrictdata has pf&d and client does not so subtract that.
            int pfanddRows = 2;
            int projectMetricDataRows = accessor.mMediaDurationDataSet.ProjectMetricData.Rows.Count;
            int copiedRows = projectMetricDataRows - pfanddRows;
            if (copiedRows < 0)
                copiedRows = 0;

            Assert.AreEqual(accessor.mMediaDurationDataSet.ClientProjectMetricData.Rows.Count, copiedRows, "project metric data copy not created");

        }

This is the inner code of the "target.OpenModel(modelID);", I get the error and straight away jump to "catch (Exception e)"), my data was empty at here "mMediaDurationDataLayer.GetModelDetails(mMediaDurationDataSet, modelID);", how do I solve the error?

public DataSet OpenModel(int modelID)
        {
            try
            {
                mMediaDurationDataSet = new MediaDurationDS();
                mMediaDurationDataLayer.GetModelDetails(mMediaDurationDataSet, modelID);

                //ConvertToLocalTime(mMediaDurationDataSet.Model, "ClientLastUpdateDate");
                ConvertToLocalTime(mMediaDurationDataSet.ModelActivity, "ClientLastUpdateDate");

                //IF MODEL IS MOR, ACT
                CreateProjectForMORModel(modelID);

                //COPY PROJECT METRIC DATA TABLE INTO CLIENTPROJECTMETRICDATA   
                foreach (MediaDurationDS.ProjectMetricDataRow pmdr in mMediaDurationDataSet.ProjectMetricData.Rows)
                {
                    //WE DONT WANT PF&D IN CLIENT TABLE
                    if (!pmdr.MetricTypeName.Equals(PFANDDPARAMETER))
                    {
                        CreateClientProjectMetricDataRow(pmdr, pmdr.ProjectMetricID);
                    }

                }           

                mMediaDurationDataSet.AcceptChanges();
                mMediaDurationDataSet.WriteXml("C:\\MediaDurationTestDataSet.xml");
                return mMediaDurationDataSet;
            }
            catch (Exception e)
            {
                string errorMessage = "Unable to retrieve Media Duration Model " +Environment.NewLine + e.Message;
                throw new Exception(errorMessage);
            }
        }



public class MediaDurationDL
{
    ProjectManagerDL mProjectManagerDL;

    public void GetModelDetails(DataSet mediaDurationDataSet, int modelID)
    {
        Database db = X.XXX.WindowsApplicationTemplate.ApplicationDatabase.DatabaseFactory.CreateDatabase();

        string sqlProcedure = "uspMediaDurationGetModel";
        DbCommand dbCommand = db.GetStoredProcCommand(sqlProcedure);
        UtilityDL.SetCommandTimeout(dbCommand);
        db.AddInParameter(dbCommand, "ModelID", DbType.Int32, modelID);

        string[] tables = new string[] { "LaborCategory", "ProcessCategory", "Media", "Activity",                   "Time",   "Model", "ModelTime", "ModelActivity", 
         "Project", "ProjectAccess", "MetricType", "ProjectMetric", "ProjectMetricData" };//, "Metric", "MetricData"};

        // RETRIEVE DATA FROM DB AND LOAD INTO DATASET
        mediaDurationDataSet.Clear();
        //PrintAllErrs(mediaDurationDataSet);
        db.LoadDataSet(dbCommand, mediaDurationDataSet, tables);
        //PrintAllErrs(mediaDurationDataSet);
    }