Hi its the first time that I encounter this problem.
My opponent just resigned, and the screen says I won
but when I try to close the window it says the game is not finished
when I check my game record or archive, it says I won by resignation
so the problem is I cant close the window now
anyone got this problem?

btw the game was only under 50 moves in total if that is relevant to this issue

Just leave the game. It won't count as an escape if your opponent has resigned.

thx, you are right

Yes this is a longstanding bug. The server knows what is right, just the client gets confused sometimes and posts the "Don't close this game!" dialog when it shouldn't. Close the game anyway (as already said) and it will all be OK.