Directly in TFA, matey:

  > Newag explains that the train were
  > blocked by a “safety system” – but in
  > the 20,000 pages of  instructions, it
  > is in vain to  find even a mention
  > of it.

No mention whatsoever in the maintenance documents. It then becomes prudent to question the intentions and fitness of the company behind such a product.

This episode puts even John Deere to shame. I'm imagine JD are enjoying themselves right now on this Friday afternoon.