Hi, assuming you are on windows 10, 7 should make much a difference at all, Force closing the client in the task manager wont make any difference, i've had this issue before. And you wont find Tera in the [Processes] tab.
Go to the [Details] tab and you can find Tera there, you'll be able to force close Tera. If you force stop TERA.exe from there and still dosent work try doing the same to Tl.exe. 
Hello, i'm not entirely sure if its a bug or intended feature, but whoever aquires skill advancemnt scrolls I - III and skill optimisaiton scrolls I and II , the + on top of the HP/MP bar will appear ( as long as you dont have any skill advancements maxed out ). Forcing you to open and either upgrade the skill. It can also be removed by banking the optimisation scrolls. I know that its a small feature, but its really annoying and I have alot of friends complaining about it aswell.
Thank you for the attention! 
