i get error message "Index out of range."

[mrMuppet]

``Start of process works:

• Extract ZIP Data gets green
• Get Streams Data gets green
• Download Assets gets green

During this there are some files downloaded and two XML- and a lot of small flv-files extracted. Then i get the following message with "go on" or "cancel" :

Index out of range. Must be non-negative and less than the size of the collection. (Parameter 'index'). 

System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')
   at System.Collections.Generic.List`1.get_Item(Int32 index)
   at AdobeConnectDownloader.Application.AudioManager.AudioLine(List`1 audioStreamDatas) in C:\My Project\Programing\WinForms\C#\AdobeConnectDownloader\AdobeConnectDownloader\Application\AudioManager.cs:line 106
   at AdobeConnectDownloader.Application.AudioManager.MatchAllAudio(List`1 audioStreamDatas, String fileName, String dataFolderPath, String outputFileFolder, String ffmpegAddress) in C:\My Project\Programing\WinForms\C#\AdobeConnectDownloader\AdobeConnectDownloader\Application\AudioManager.cs:line 23
   at AdobeConnectDownloader.UI.ProcessForm.<MergeAllFiles>b__79_0() in C:\My Project\Programing\WinForms\C#\AdobeConnectDownloader\AdobeConnectDownloader\UI\ProcessForm.cs:line 262
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
   at AdobeConnectDownloader.UI.ProcessForm.MergeAllFiles() in C:\My Project\Programing\WinForms\C#\AdobeConnectDownloader\AdobeConnectDownloader\UI\ProcessForm.cs:line 170
   at AdobeConnectDownloader.UI.ProcessForm.WebManager_DownloadFileCompleted(Object sender, AsyncCompletedEventArgs e) in C:\My Project\Programing\WinForms\C#\AdobeConnectDownloader\AdobeConnectDownloader\UI\ProcessForm.cs:line 157
   at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__128_0(Object state)
   at InvokeStub_SendOrPostCallback.Invoke(Object, Span`1)
   at System.Reflection.MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)