Questing Bug (Error: NPC not found)

I was doing the quest "Break the Talisman"

As I was running at the Baron (Boss) I clicked the pirates icon, it then said quest complete and offered me my reward, my pirates screen was then interrupted by the boss fight with Baron, (I lost) but it still allowed me to continue to the next quest. However now when I run into an enemy, it comes up with an error NPC not found and hangs at the word "Engaging.."

Could you look into this please, as I am not unable to continue with any of the quest line.

Thanks,
Tim