An unhanded exception occured.

[MagicAndre1981]

With 3.1.15 on older 1809 LTSC with .net 4.8 I get this NRE at startup

An unhanded exception occured.

At this point you can opt to continue, however it is possible that the aborted computation will cause additional failures.   Because PerfView generally only opens files for reading, there is no danger of corrupting  files, so it generally does not hurt to try.   However be on guard for unusual/incorrect behavior going forward.

You can of course exit and restart PerfView to be completely safe.

The fact that this exception went unhanded is a programmer error.   It should be reported so it can be fixed.  Please set along the following stack trace information which will be useful in diagnosing the problem.

StackTrace:
System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.
   bei PerfView.GuiApp.OnGuiUnhandledException(Object sender, DispatcherUnhandledExceptionEventArgs e)
   bei System.Windows.Threading.Dispatcher.CatchException(Exception e)
   bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   bei System.Windows.Threading.DispatcherOperation.InvokeImpl()
   bei MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
   bei System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   bei MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
   bei System.Windows.Threading.DispatcherOperation.Invoke()
   bei System.Windows.Threading.Dispatcher.ProcessQueue()
   bei System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   bei MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   bei MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

// Edit:

3.1.13 works fine. So I made a rollback for now.