The world I'm using is about 780MB (or the backup is). I have a village that I built up over two years as my "home base". The village is full of villagers, iron golems, livestock, fields, gardens, some redstone driven automation, and so on. I'm currently running in easy mode survival, as is mu custom with a new beta.

I entered one of the cave+tunnel complexes under the village during the evening, and discovered that I have lost the ability to control the direction my avatar is facing. The direction arrows for movement are laggy, but function, and I can get in and out of inventory. Actions stick for a long time - my pickaxe took out a wall before I could stop it, and I've been unable to navigate out of the mess I've made .

I suspect this is due to the huge population directly overhead that I cannot see but is in the loaded chunk.

I have not experienced these symptoms in the past with this world and location.

I'm willing to upload the world if that would help.