I'm not sure if this is happening to everyone, but for a short amount of time, the Base is closed. Google Chrome says that it can't be found, but I can see the icon. Whats going on, am I the only one?
Yes, as others have stated, it occurs regularly. No, you shouldn't worry, as it is all part of routine maintenance.
Without daily maintenance, the servers that NB uses could be detrimentally impacted and cause some issues.