Synthesizer does not support new pronunciations
Your VoiceXML document contains the unsupported element <ibmlexicon>. In this condition, dtjstart is successful and the speech browser is running, but the error is generated when the unsupported element is found. The caller might not hear exactly what they expected, but VoiceXML document processing continues normally to completion. This message is specific to <ibmlexicon> but it is really an unsupported element error.
Remove the unsupported element<ibmlexicon> from your VoiceXML document and use a supported element.