[Help] I got this error message when trying to start recording

[Lulusan-Concept]

Error: System.Exception: Call in Start failed: -2 Unknown error function
at SysDVR.Client.Core.Exten.FailImpl(String message)
at SysDVR.Client.Core.Exten.AssertZero(Int32 code, Func`1 MessageFun, String caller)
at SysDVR.Client.Targets.FileOutput.Mp4Output.Start()
at SysDVR.Client.GUI.PlayerView.ButtonToggleRecording()

I got this error message when trying to record NS using SysDVR. How can I Fix it?