Storyline problem

?xml version="1.0" encoding="utf-16"?>
<ErrorReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<UserId>aid|ac2625f6-2186-4499-8fcc-d8e7b62e68bf</UserId>
<HardwareId>9U7R0-DE3F9-1UAUU-9VT1P-R9CKX</HardwareId>
<Message>Object reference not set to an instance of an object.</Message>
<StackTrace> at new Articulate.Design.Publish.QuizSubmissionViewModel((IQuiz quiz, QuizSubmissionType submissionType) quizTypeCalculator, SubmitTriggerProvider submitTriggerProvider)
at Articulate.Design.Publish.WpfTrackingBlockViewModel(IQuizManager quizManager, bool showLmsInfoBox)+((IQuiz quiz, QuizSubmissionType submissionType) submittableQuiz) =&gt; { }
at Func&lt;TSource, TResult&gt; System.Linq.Enumerable.CombineSelectors&lt;TSource, TMiddle, TResult&gt;(Func&lt;TSource, TMiddle&gt; selector1, Func&lt;TMiddle, TResult&gt; selector2)+(TSource x) =&gt; { }
at bool System.Linq.Enumerable+WhereSelectEnumerableIterator&lt;TSource, TResult&gt;.MoveNext()
at new System.Collections.Generic.List&lt;T&gt;(IEnumerable&lt;T&gt; collection)
at List&lt;TSource&gt; System.Linq.Enumerable.ToList&lt;TSource&gt;(IEnumerable&lt;TSource&gt; source)
at new Articulate.Design.Publish.WpfTrackingBlockViewModel(IQuizManager quizManager, bool showLmsInfoBox)
at new Articulate.Design.Publish.WpfLmsLrsReportingTrackingViewModel(ILmsData lmsData, IQuizManager quizManager, bool reportingTabs, int activeIndex, Action&lt;string&gt; showWarning)
at new Articulate.Design.Publish.WpfLmsLrsReportingTrackingDialog(ILmsData lmsData, IQuizManager quizManager, bool reportingTabs, int activeIndex)
at bool Articulate.Design.Publish.ReportingTrackingDialog.ShowReportingTrackingDialog(IQuizManager quizManager, ILmsData lmsdata, bool reportingTab, int activeIndex)
at bool Articulate.Storyline.Publish.exLmsLrsTarget.a(ILmsData A_0)
at void Articulate.Storyline.Publish.exLmsLrsTarget.ShowReportingUI()
at void Articulate.Design.Publish.LmsLrsTarget.aq(object A_0, EventArgs A_1)
at void System.Windows.Forms.Control.OnClick(EventArgs e)
at void System.Windows.Forms.Button.OnClick(EventArgs e)
at void Articulate.Windows.Forms.Metro.MetroButton.OnClick(EventArgs e)
at void System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at void Articulate.Windows.Forms.Metro.MetroButton.OnMouseUp(MouseEventArgs mevent)
at void System.Windows.Forms.Control.WmMouseUp(ref Message m, MouseButtons button, int clicks)
at void System.Windows.Forms.Control.WndProc(ref Message m)
at void System.Windows.Forms.ButtonBase.WndProc(ref Message m)
at void System.Windows.Forms.Button.WndProc(ref Message m)
at void System.Windows.Forms.Control+ControlNativeWindow.OnMessage(ref Message m)
at void System.Windows.Forms.Control+ControlNativeWindow.WndProc(ref Message m)
at IntPtr System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, int msg, IntPtr wparam, IntPtr lparam)</StackTrace>
</ErrorReport>