After every game update, Attack and Defense logs will be missing certain information. Attacks may not show any units being used, and both Replay and Revenge buttons will be unavailable for certain attacks. This display issue occurs when the attacker and defender are playing different versions of the game.
The best way to resolve the problem is to download the latest update as soon as possible. This will not recover all of the previous Attack and Defense information, but once everyone in the game completes the update, all new battles will display this information properly.