Неопределенная функция' Nz ' в выражении

я погуглил эту ошибку и не сделал вывод о том, почему я получаю эту ошибку. Я пытаюсь заполнить DataGridView некоторыми данными. Вот мой код.

Private Sub LoadGrid()
    Dim cmd As New OleDbCommand
    Dim dt As DataTable
    With cmd
        .CommandText = "project_master_query"
        .CommandType = CommandType.StoredProcedure
        .Connection = New OleDbConnection(My.Settings.cnnString)
    End With
    dt = GetData(cmd)
    dgvData.DataSource = dt
End Sub

Private Function GetData(ByVal cmd As OleDbCommand) As DataTable
    Dim dt As New DataTable
    Using cmd.Connection
        cmd.Connection.Open()
        dt.Load(cmd.ExecuteReader(CommandBehavior.CloseConnection))
    End Using
    Return dt
End Function

запрос "project_master_query" хранится в Access.

    SELECT project_master.*, location_master.LocationName,
    project_currentmilestonedef.MilestoneDefID, 
    project_currentmilestonedef.MilestoneName, project_regions.RegionName,
    owner_fullname.FullName AS OwnerFullName, designer_fullname.FullName AS DesignerFullName,
    project_issuecount.HasOpenIssues, project_updated_closedate.UpdatedCloseDate, 
    project_bonusdays.BonusDays, project_bonusdays.IsGreen, project_bonusdays.IsYellow, 
    project_bonusdays.IsRed, checklist_days_perproject_defined_1.Week1, 
    checklist_days_perproject_defined_1.Week2, checklist_days_perproject_defined_1.Week3, 
    checklist_days_perproject_defined_1.Week4, project_issueduration.ProjectIssueDurationDays, 
    project_active_status.ProjectIsOpen, project_requirement_status.RequirementStatusName, 
    priority_def.PriorityShortName
    FROM project_requirement_status 
    RIGHT JOIN (project_regions 
    RIGHT JOIN (priority_def RIGHT JOIN (location_master 
    RIGHT JOIN ((((checklist_days_perproject_defined AS checklist_days_perproject_defined_1 
    RIGHT JOIN ((((((((contacts_fullname AS designer_fullname 
    RIGHT JOIN (contacts_fullname AS owner_fullname 
    RIGHT JOIN project_master ON owner_fullname.ContactID = project_master.ContactOwner) 
    ON designer_fullname.ContactID = project_master.ContactDesigner) 
    LEFT JOIN project_issuecount 
    ON project_master.ProjectID = project_issuecount.ProjectID) 
    LEFT JOIN project_currentmilestonedef 
    ON project_master.ProjectID = project_currentmilestonedef.ProjectID) 
    LEFT JOIN project_within_benchmark_week1 
    ON project_master.ProjectID = project_within_benchmark_week1.ProjectID) 
    LEFT JOIN project_within_benchmark_week2 
    ON project_master.ProjectID = project_within_benchmark_week2.ProjectID) 
    LEFT JOIN project_within_benchmark_week3 
    ON project_master.ProjectID = project_within_benchmark_week3.ProjectID) 
    LEFT JOIN project_updated_closedate 
    ON project_master.ProjectID = project_updated_closedate.ProjectID) 
    LEFT JOIN checklist_days_perproject_defined 
    ON project_master.ProjectID = checklist_days_perproject_defined.ProjectID) 
    ON checklist_days_perproject_defined_1.ProjectID = project_master.ProjectID) 
    LEFT JOIN project_issueduration 
    ON project_master.ProjectID = project_issueduration.ProjectID) 
    LEFT JOIN project_active_status 
    ON project_master.ProjectID = project_active_status.ProjectID)    
    LEFT JOIN project_bonusdays ON project_master.ProjectID = project_bonusdays.ProjectID) 
    ON location_master.LocationID = project_master.Location) 
    ON priority_def.PriorityDefID = project_master.ProjectPriority) 
    ON project_regions.RegionID = project_master.Region) 
    ON project_requirement_status.RequirementStatusID = project_master.RequirementStatus;

Как вы можете видеть, в запросе нет Nz, поэтому я не понимаю, почему это происходит вообще. Ошибка возникает после dt.Нагрузка вызывается.