I have tried to install livery's on pmdg 737ngx via livery manager and everything works accordingly on the livery manager but i cant see the livery on the aircraft's in the aircraft select option . Ive reinstalled pmdg 737ngx and still no luck .

 

Hkhan

Make sure that you click the check mark in the select an airplane menu that says "show all variants" that should do it.

all the variants are there + their is no menu to show all variant's i have version 1.12

"show all variants" is on the aircraft selection page in FSX, not in the Livery Manager.