Unfixed Chunk Error

Two areas of major chunk-errors(unspawned zones down to the void) in a close area to where I and many others have put 50 hours+ of building.

Level has been open to LAN, and used as a server.

Reloading, exiting, placing blocks next to area (etc.) does not help.

Forced crash for possible help. Text File Attached.

I cannot find any answers online, though many similar have been posted. I just need a way to respawn those points.