When a voice broadcast does not run when you click run the "Run Voice Broadcast" please check your Do not call before and Do not call after time settings for that capaign.
If it is current time does not fall in this configured window then the campaign will not run. Please wait untill the configured time or change your campaign settings.
Also please check to see if there are remaining contacts in your list. If there are no more available contacts then the dailer will not run.