It’s a warning so may not be something to worry about. Are all your add-ons installed and functioning? If so, it’s probably just an unexpected cache miss or there was a clear the cache or something and OH went back out to the internet to pull and install the add-ons.
seems like everytime now, but I’m pretty sure it was not always like that. So might be when I updated one of the addons manually (WeatherCalculations). Not sure tho.
If it’s consistent and happens all the time it’s probably worth filing an issue. At a minimum the logs should be DEBUG if it’s not something worthy of note. But I bet it points to a bug.