Error: "Unexpected nil index path in _canPerformAction:forCell:sender:, this should never happen."

Error: "Unexpected nil index path in _canPerformAction:forCell:sender:, this should never happen."

I have a dynamic tableView with 2 prototype cells. I using one of the cells for section header, the section header cell has it's own class. Data have been populated to these cells without problems.

I am getting this error message at runtime, and when I tap on the section header. Anyone knows how to get rid of this error? Thanks in advance

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

            let cell = tableView.dequeueReusableCell(withIdentifier: "MachineTableViewCell") as! MachineTableViewCell
      
            if self.uptime.count == self.machines.count {
                cell.GPUNumber.text = self.allGPUNumber[indexPath.section][indexPath.row]
            }
            return cell
    }

   
    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        /
  
        guard let header = tableView.dequeueReusableCell(withIdentifier: "header") as? HeaderTableViewCell
            else {
                return nil
            }
  
        let machine = machine[section]
        header.name.text = machine.name + " - " + machine.ip + ":" + machine.port
        return header
    }

    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat
    {
        return 124
    }