reached lv lancer and got a new skill

[KoroushSensei]

i have it but cant use it because it says i have not learned it. how do i learn it

[Vandril]

Which skill are you talking about?

Were you level synced to lower level content from before you learned the skill? Maybe you were doing a FATE that required a level sync? When you're level synced, you temporarily lose access to skills above the level you're synced to.