Okay, I am reinstating the server. However, I have had to rollback part of the world to our backup from early morning Jan 29. It is the recent that the chunks version that doesn't have missing chunks.
This doesn't affect much of the world, just the area around x=1086, z=112. It will unfortunately undo some of the work of one player - Tribble. I have taken before and after shots and the Admin team will help you out with some of what has been undone. Luckily though, your building and wall are still there. It will be your machinery and farms that have gone.
For those who wonder, here are the before and after shots of the holes.
Fascinating aren't they... not. Look like evil eyes to me. The complaint from the server was about the Mo's creatures in the river and on the land. It kept trying to position them in the void and failing. The server also was complaining about chunks not being in the right place and it repositioning them. I have never seen these error messages before. Something more to hunt down.
So in brief - Tribble's land rollbacked a couple of days, the rest of the server unchanged.
Tell us if you find any more permanent holes (rather than holes that disappear if you log out and in again).