Well in my home i made a L2,but in my brother home i cant do that..i had same problem,i dont know how - but i fixed it and i can play from home,but from brother's home i cant - look picture and tell me if u know why is that...
http://img837.imageshack.us/i/5555555555555c.jpg/
P.S I remember,i did restart on my pc because i had this problem and after restart all was ok ,i opened rpg.exe and the game was ok,but here there is any problem who i cant fix...
You're missing .net framework. Just install it.