I did finish a quest of Scholar Ascension where i learned how to use the shift + lmb and shift+ rmb skills but right after, the quest is bugged and I can't continue since i can't talk with the cube anymore. The quest I'm at right now is [Scholar Ascension] Combat Ability Recovery Protocol. Also, when i try to call the black spirit i get a "This action cannot be executed at this moment".

EDIT: I did what Amanohara did but instead i re-entered the game.

Up, same thing for me as well

UPDATE: Forfeit the quest, switch to a different character and back to Scholar and it should allow you to proceed with restarting the quest and forward.

I restarded the game and fixed the bug.

Restart the game worked