Guild Wars 2

Hello, this morning while walking through lion’s arch, some red and green lines began to appear on my screen. I was like, it’s nothing so I re-launched the game and they were gone. But when i went in Sparkfly fen to fight Tequatle, these lines came back but this time began to do some sort of drawings. I’d like to know if it’s a problem due to things in/on my computer, or if it’s just a bug. Thanks for your replies, have a good day.

sometimes things like your picture are caused by the game’s files going a little screwy. if it is because of that you could try repairing the game client. here’s a link to how:
https://help.guildwars2.com/hc/en-us/articles/201863008-Repairing-the-Game-Client

if the client seems to do nothing, or stop responding during the repair, just leave it. it does it to some, but will continue after 5 mins or so, so just leave it and do something else.