hello Ive been using minecraft with my son for a year or so without any incident (wish my apps ran that well).
I was working on a map with my son. We saved as normal but on reload sections of the map have inexplicably moved of their own accord, seens like some sort of sequencing error as the map saved, i dunno.
i have attached screen shots of the problem. Is there any way this can be fixed without manually rebuilding?
I've never heard of chunks moving before. What I know can happen is one of two things, only one of which might apply.
1) When creating a world with the same name as a previously deleted world, the same save directory is used. If the first world failed to be completely deleted then the undeleted chunks will be loaded into your world. This is because the world is just a loosely affiliated collection of files stored in the same directory structure. The data for location (X,Y) is stored in the same file name in all saves and the game doesn't know that the files are inconsistent. I don't think this applies to you.
2) If a file in your save is damaged / corrupted, then MC will not be able to load it and display that section of your world. Two things can happen at that point, MC shows an unloaded 'hole' or MC displays what would have been there in the original virgin world by generating the chunk using the world seed, settings, and world generator code. Whether this regenerated chunk looks like the original chunk to you or not depends upon whether your seed is identical to its starting value, and whether the world generator code has changed across MC versions. Another side effect that can happen when this happens is that MC may or may not overwrite the corrupted file with the regenerated chunk. If it doesn't overwrite it then this chunk will keep reverting to the virgin state every time you load the chunk. I think that this applies to you. It's a little hard to tell not knowing what your world is supposed to look like, but it looks to me like you have virgin chunks popping up.
I was working on a map with my son. We saved as normal but on reload sections of the map have inexplicably moved of their own accord, seens like some sort of sequencing error as the map saved, i dunno.
i have attached screen shots of the problem. Is there any way this can be fixed without manually rebuilding?
I've never heard of chunks moving before. What I know can happen is one of two things, only one of which might apply.
1) When creating a world with the same name as a previously deleted world, the same save directory is used. If the first world failed to be completely deleted then the undeleted chunks will be loaded into your world. This is because the world is just a loosely affiliated collection of files stored in the same directory structure. The data for location (X,Y) is stored in the same file name in all saves and the game doesn't know that the files are inconsistent. I don't think this applies to you.
2) If a file in your save is damaged / corrupted, then MC will not be able to load it and display that section of your world. Two things can happen at that point, MC shows an unloaded 'hole' or MC displays what would have been there in the original virgin world by generating the chunk using the world seed, settings, and world generator code. Whether this regenerated chunk looks like the original chunk to you or not depends upon whether your seed is identical to its starting value, and whether the world generator code has changed across MC versions. Another side effect that can happen when this happens is that MC may or may not overwrite the corrupted file with the regenerated chunk. If it doesn't overwrite it then this chunk will keep reverting to the virgin state every time you load the chunk. I think that this applies to you. It's a little hard to tell not knowing what your world is supposed to look like, but it looks to me like you have virgin chunks popping up.
There are map editing tools that can repair some corrupted chunks so you might want to check these out. I'm not familiar with these tools and you should definitely make a backup copy of your world before trying any of them out. Here's an example tool: http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-tools/1261480-minecraft-region-fixer