SWTOR Balmorra Sith Warrior : conversation with Lieutenant Quinn never advancing

I've been playing SWTOR for a year, never had any bug up until now. Now I'm playing a Sith Warrior and at the end of the class story on Balmorra, I'm stuck in a conversation with Lieutenant Quinn. He says one line, then, after my character's response, nothing happens. The cutscene is not advancing. It's not frozen, but it never advances. The convo never finishes. It's forever stalled after two lines. 

I tried pressing spacebar, 1, esc, logging out and coming back, leaving the area, leaving the planet and coming back...Nothing worked. The convo always stays the same. 

I can't reset or abandon the quest because it's my class storyline. 

Is there any solution or is my character basically dead ? Because if I can't complete my class mission I can't advance...