The Dutch Council of the State allowed not to make public the details of the MH-17 tragedy for two reasons. 1. The investigators have no hard facts and they are afraid that their conclusions will be disproved. 2. Ukrainian side has asked to keep it in secret because most probably Ukraine is guilty for the tragedy.
Reccuring MH17-related disinformation. According to the Council of State, it is necessary that the information remains confidential, as it is likely that disclosure thereof could jeopardize the proper functioning of the committee. The Council found this more important than the interest of disclosure. "The interest of disclosure does not outweigh the interest protected by the refusal, such as the relations of the Netherlands with other states and international organizations, respect for the privacy of the parties involved and the protection of personal policy views", the Council ruled.
Joint Investigative Team (JIT) has concluded that flight MH17 was shot down on 17 July 2014 by a missile of the 9M38 series, launched by a BUK-TELAR, from farmland in the vicinity of Pervomaiskiy (or: Pervomaiskyi). At that time, the area was controlled by pro-Russian fighters. The BUK-TELAR was brought in from the territory of the Russian Federation and subsequently, after having shot down flight MH-17, was taken back to the Russian Federation.
More on background of the MH17-related disinformation here.