mscorlib - value cannot be null - parameter name: value

Question

I have a VB.net application that has been built for awhile. I recently added a barcode in active reports 6 to one of the reports.

everything works fine on my machine as well as others, but a select few get an error relating to the following:

mscorlib - value cannot be null - parameter name: value

there code is as follows:

Dim rp As New ARPTSpecialOrderCard
CType(rp.Sections("pgDetails").Controls("labelVendorPhone"), DataDynamics.ActiveReports.Label).Text = Me.LabelVendorTelephone.Text
CType(rp.Sections("pgDetails").Controls("labelID"), DataDynamics.ActiveReports.Label).Text = Me.orderid.ToString
CType(rp.Sections("pgDetails").Controls("bcID"), DataDynamics.ActiveReports.Barcode).Text = Me.orderid.ToString
rp.Run()
frmARViewer.Viewer1.Document = rp.Document
frmARViewer.ShowDialog()

Exception text:

> ************** Exception Text ************** System.ArgumentNullException: Value
> cannot be null. Parameter name: value 
> at
> System.Collections.CollectionBase.OnValidate(Object value)    at
> System.Collections.CollectionBase.System.Collections.IList.Add(Object value)    at
> DataDynamics.ActiveReports.Document.FontsCollection.Add(Font inFont)    at
> #f.#iZi.set_Font(Font value)    at
> DataDynamics.ActiveReports.Label.#Pvb(GraphicsCache cache, Page page, PointF pageOffset, Single startPos, Single endPos)    at
> DataDynamics.ActiveReports.ARControl.Render(GraphicsCache gRef, Page page, PointF pageOffset, Single startPos, Single endPos)    at
> DataDynamics.ActiveReports.Section.Render(GraphicsCache cache, Page page, #Ppb drawingLog, PointF pageOffset, Single pageWidth, Single drawStartPos, Single drawEndPos)    at
> DataDynamics.ActiveReports.Section.Render(GraphicsCache cache, #rqb rData, #Ppb drawingLog)    at
> #mb.#mqb.#LDb()    at
> #mb.#mqb.#SDb(Section section, Int32 insPos)    at
> #mb.#vqb.#vEb()    at
> #mb.#vqb.#qEb(Page newPage, Single left, Single top, Single right, Single bottom, UInt32 flags, UInt32& status) at
> DataDynamics.ActiveReports.ActiveReport.#4yb() at
> DataDynamics.ActiveReports.ActiveReport.Run(Boolean syncDocument)    at
> SpecialOrderSystem.soFRMViewOrder.pbPrintPO_Click(Object sender, EventArgs e)    at
> System.Windows.Forms.Control.OnClick(EventArgs e)    at
> System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)  at
> System.Windows.Forms.Control.WndProc(Message& m)    at
> System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)    at
> System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Do I need to update the mscorlib.dll on the users machine? I'm not sure why this error is happening.

thanks