I was in the process of answering you against the grain here, as everyone was saying it is index related and that is not always true in my experience, just 3 weeks ago I was chasing the same problem and the error name got me chasing ghosts, as I also thought it was index related, but it turns out it was not, now, I asked my co-worker and he also forgot what did I tell him the problem was, that is why I did not reply, I am looking into the tickets to try to find out what it was and how did I solve it, unfortunately, I cannot find it, I think it might have been that the file grew past 2Gb, so I am trying to test that now, but if that was the case, it will not help you at all
"The five senses obstruct or deform the apprehension of reality."
Jorge L. Borges?
"Premature optimization is the root of all evil in programming."
Donald Knuth, repeating C. A. R. Hoare
"To die for a religion is easier than to live it absolutely"
Jorge L. Borges