How to debug crash - Thread 1: EXC_BAD_INSTRUCTION (code=1, subcode=0x40343276)

I have a strange crash on iOS device (EXC_BAD_INSTRUCTION). I have a custom UIControl called ScrollingScrubber and all it has is a UIScrollView, and it fires .valueChanged events when user is scrolling. That's where sometimes the crash happens and I have no idea how to debug it further.

      var value:CGFloat = 0

      override open func beginTracking(_ touch: UITouch, with event: UIEvent?) -> Bool {
        isUserDragging = scroller.isDragging
    
        if isUserDragging {
           sendActions(for: .editingDidBegin)
        }
    
        return isUserDragging
     }


    override open func continueTracking(_ touch: UITouch, with event: UIEvent?) -> Bool {
    
         value = (scroller.contentOffset.y + scroller.contentInset.top)/(scroller.contentSize.height)
    
          sendActions(for: .valueChanged) //It sometimes crashes here with EXC_BAD_INSTRUCTION, why?????
    
          return true
    }