Some countries has reported that they have some problems issuing the new certificates before the deadline. The IMO has asked member countries to have a pragmatic approach during port state control from 1 January 2017. The Paris MoU has decided to have a harmonized approach in line with the recommendation from the IMO - MSC.1/Circ.1560.
More info: https://www.parismou.org/inspection-certification-seafarers-under-stcw-after-1-january-2017