Appeals Committee. Disputed situations in tournaments.

But shouldn't the members of the AC write something?

Formulate your question. Or are you just letting the AC know that your fellow player can't open the save file?
If there are any complaints about the game, specifically suspicions of cheating, you should first write: 1) the opponent's nickname; 2) their AC number; 3) where and how you played, and generally formulate your own thoughts, and if the opponent tried to explain their actions, post excerpts from the conversation here. Only after that can the situation be analyzed.