Logged out yesterday with no issue. Log in today and every herb/mining node I had is gone. My setting seem to be the same as always. The gatherer database is virtually empty. What happened? Where can I look for the datafile?
your data file got corrupted, most likely. did the closing of wow happen normally, or was there a hiccup of some sort? the data file is in the WTF directory, and is called Gatherer.lua (not the one in the Interface folder).
unfortunately, unless you have a backup, there's not much you can do about it. we are hoping there will be an updated wowhead node database available soon, but we are not in control of when it gets released.
When you say "Gatherer database is empty", does that mean you actually opened a database and it showed you no nodes? If no... May be you just accidentally clicked the Gatherer icon? And it just not showing node locations?