I've experienced this a couple of times in the last days. At some point in the game, without any noticable pattern, the client freezes (in Firefox 51.0.1 (32-Bit)). It has happened during my own turn and in my opponent's. When I refresh, I'm taken to the table creation page without any hint about the last game.
This time I've taken the time to just wait and see what happens. After several minutes I was taken to the game result screen, which tells me that I resigned, which I didn't. The game log now shows my opponent's last turn (T12) and also the chat has updated.
When I reloaded the game, I could continue to play with Lord R until the end.
The original game was #2213574 on tokyo. This is very annoying. Could you please investigate what the problem is?