This error message has popped up a few times. The pattern always seems the same, at least so far.
- Focus for X minutes.
- Turn off my iPad.
- Turn on my iPad after X minutes have elapsed.
- Game resumes right where I left off, as expected.
- Sometimes, but not always, this error appears immediately. Click OK if it does appear to dismiss it.
- Collect the focus reward.
Other than having to dismiss the error message sometimes, nothing seems to be wrong. Game plays normally after message is dismissed. (And there is no need to try again later.)