i had installed my gallery and suddenly i was getting this error, but this appears to have something to do with the "g2_lock" table in the gallery2 database. It appears that if there's an error on the gallery, it adds a "lock" that's good until a certain date. If you open up the g2_lock table, change the value of "g_freshUntil" to "0", then the gallery should work again. NOTE: This problem appears all over the forums but I haven't seen a single answer; this fix worked for me and I'm hoping someone will come along with a more comprehensive solution.