i just found that what a nightmare for him and Tech3 team....
https://www.motoservices.com/actualite-competition/MotoGP-2018-Folger-ne-roulera-pas.htm
MotorCycleNews
https://www.motorcyclenews.com/sport/motogp/2018/january/motogp-folger-to-sit-out-2018-motogp-season/