Lag and Error 90002

Since the recent update (emergency update due to something happening in Alexander I think), the game has been lagging and d/cing. I cant do a dungeon now due to d/cing in the middle of it. If I am not in a dungeon, my character seems to move freely. However, the characters around me seem to freeze/skip. Also, sometimes when I try to get on a mount, it skips sometimes before I am on my actual mount. I also got error 90002 after getting disconnected from a dungeon. It is basically unplayable. I think it might have something to do with the recent update that occurred since I had no problems until then. Thank you.

It must be some issue with computer. I tried it on my old laptop, and the issue wasn't there. However, this is the new laptop that I will play the game on. Does anyone have any idea what the issue is? Thank you.