To clarify a bit more:
Sometimes services will fail when requesting data to buid the downloads. This can cause the download process to have issues and never finish generating the cached file. Dropping the download cache via the ‘Resync button’ restarts this process.
We are adding more processing checks to hopefully prevent these intermittent issues from occurring, you’ll see those start to show up very soon. We are also working on alerting you when there are download errors.