Two examples from Diabetes research of non-reproducible studies. A commentary on The Scientist published on August 10th, 2018.
There will always be reasons why studies cannot be replicated and that can be to the smallest experimental details. This is ok and will always happen in research. However, it is not ok, that this is not openly discussed and that the other of the original papers apparently did not respond when contacted by The Scientist. Science lives from the dialogue and the constructive discussions between different researchers. Only as a community it will be possible to advance our knowledge and make break through progresses.