Alphazero15:I'm having this exact same problem! I blamed it on a virus my parents got, but maybe its not that...
Actually, I just fixed it! Here's how I did it: Go to my computer, click on C:. Then go into the Nexon folder, and go in the Mabinogi folder. Then click on the HShield folder. Finally, click on the Update folder, and run autoup.exe!
That fixed it for me, hope it works for you.