First, make sure you have the most current version of the software - the newest update allows off-line food tracking, which would make your error message old news, I would think. Then, I'd turn my phone completely off and on again.
If you are still having the problem, I recommend deleting the software, reboot phone again and then ownload the software again.
All these steps solve the majority of problems. If you are still getting an error message after doing them, then we have to kick it up to the tech team for review. Let us know whether we'll need to do that.
Those who think they have no time for a healthy lifestyle will sooner or later will have to find time for illness.