You deploy a dual tone multi-frequency (DTMF) based Interactive Voice Response (IVR) application. The application is developed by using Microsoft Lync Server 2010, Unified Communications Managed API 3.0 (UCMA3.0) Workflow Speech controls.
The application contains a SpeechQuestionAnswerActivity and an associated ConsecutiveNoInputsSpeechEventActivity, ConsecutiveNoRecognitionsSpeechEventActivity, SpeechHelpCommandActivity, or SpeechRepeatCommandActivity. These event or command activities contain a StatementActivity or SpeechQuestionAnswerActivity.
A user connects to the application, and then the user starts pressing DTMF digits while a question message plays back.
The application stops playing the question message and stays silent, and then the user disconnects.
In this scenario, the UCMA 3.0 workflow IVR application crashes. Additionally, you receive the following error message:
System.NullReferenceException was unhandled Message=Object reference not set to an instance of an object. Source=System.Workflow.ComponentModel
This issue occurs because an event or command activity is initiated before the question message has completed playing. Then, internal events occur out of order and cause an unhandled runtime exception in the Windows workflow platform.
To resolve this issue, install the following update.
For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
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