The reason there has been no update is because r81 is one of the first beta updates, intended for testing only, and likely to introduce new problems (and lo and behold, it did). If you want to avoid newly introduced problems, stick to stable releases - just set your update checking preference to stable updates only, and only install updates Construct 2 prompts you about. Otherwise you're opting in to test possibly broken new releases. I think we need to make this clearer though because a number of people seem to have run in to this thinking they're on a stable release for some reason.