@GauravT47983100 ,

please check whether the event name you’re using is actually being queued (you can check System Logs > Events to see if your sn_si.TaskAssigned appears), and if not you’ll need a Business Rule or Flow on the sn_si_task table that fires gs.eventQueue('sn_si.TaskAssigned', current, current.sys_id, current.assigned_to) after a record update so that your Notification (set to When: Event is fired with that event name) can trigger properly, plus ensure the notification conditions, recipients and user email fields are all valid (for example that the user is active and has a correct email address) for notification engine to process it.......

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