We export the world from xbox360 (using both Modio and Horizon), when we load it on the PC, it looks like the main xbox map was literally dropped into another PC world--the mountains on this world are half-missing, sheared right through with laser precision. The biomes do not match where the shears occur, i.e. desert biomes immediately next to forest with no blending. One of the structures we built, a sizeable castle, is only about 20% there, the rest "sheared away," covered by ocean. In fact, the bulk of the structures and terraforming are absent, apparently under water, not literally, just replaced by a seed that is heavily ocean/islands. Closer inspection of the regions show that r.0.0.mca was associated with an entirely different world seed. I manually edited the seed back to the proper one, but our structures are still missing in game. Looking at the map with UME (Universal Minecraft Editor) shows that the original map and all the structures are still there, just not accessible in game. I've tried using other tools like MCEdit, MCC Tool Chest and the Minecraft Map Converter, all with no success. Using different versions of Horizon or Modio still yields in the "corrupted" world. R.0.0..mca is the quadrant where the bulk of the structures we built reside. I have moved other worlds over without problems. I have posted for help on PlanetMinecraft, MinecraftForum, and contacted the people at WeMod -- none of which has resulted in any answers. Everyone seems perplexed by this. We have put a LOT of effort, many hours over many months, into the structures of this world and would like to recover them, but they can't be recovered when the software(s) can't see them. Can anyone suggest a solution?
With world conversion for Minecraft Console Legacy Xbox 360 Edition, if your world is TU 44 or before that update (As that was the last title update the third party tool I'm going to recommend worked consistently), if you can find a copy of Carnage the Creator's Minecrap Map Convertor, you can use that to convert your Xbox 360 World to a Java Edition format once you used Horizon to extract the gamesave.
The only glitches from it should be Acacia and Dark Oak tree conversion where the leaves get converted to logs and the logs get converted to leaves. You will also lose your inventory, ender chest inventory, and enchantment level upon conversion, so put your inventory and ender chest inventory in a regular chest before converting. Your enchantment level will not be recoverable and you will start out with 0 enchantment level post conversion.
From there, you create a new world on Minecraft Windows 10 Bedrock Edition, save and quit. From there, open the Bedrock world using MCC ToolChest PE. Click the map icon to open the world map, turn on region grid, right click each region and delete all the regions. Now exit out of the world map and use the 'Convert to Bedrock' function under the Tools tab, Convert sub bar.
Select your Java World file in the Java World file URL bar on your computer and hit convert. Once the conversion is complete, save the file, and close MCC Tool Chest PE. You are welcome to check your level.dat file for anything that may force the game to put your world in Creative Mode and change it if needed first.
Now load up Minecraft Windows 10 Bedrock Edition and open up your world. If there are no villagers, you will have to re-open the world using MCC Tool Chest PE and give yourself some villager spawn eggs if your world is strictly survival, or if your world is in creative mode, just give yourself some and repopulate the villages.
If your Xbox 360 world is post TU 44, I cannot ensure that Carnage the Creator's Minecraft Map Convertor will work, as on Youtube it seems to be hit or miss from that point forward. You are welcome to try this method but with a post TU 44 world, it is not a guarantee it will work. Also do not use the Andromeda Minecraft Converter on Windows 10, as it is $9.99 and MCC Tool Chest PE is free to begin, and Andromeda seems to work better as a World Corrupter if you transfer a world from Java to Bedrock Edition (It's neat having it take parts of the 360 Nether and End and mash them into the Overworld, but not worth paying $10); MCC Tool Chest PE works way better.
Alternatively, if you own Minecraft Xbox 360 Edition, a physical copy of Minecraft Xbox One Edition, a digital copy of Minecraft Bedrock Xbox One Edition, and Minecraft Bedrock Windows 10 Edition, then you can transfer any number of worlds provided you are paying for realms.
Basically, you would upload your Xbox 360 World Save for Minecraft Xbox One Edition, then retrieve the World save on Minecraft Xbox One Edition. Then on Minecraft Bedrock Xbox One Edition, you convert and import the game save. From there, you upload it to Minecraft Bedrock Realms, where you can then download it from Realms on Minecraft Bedrock Windows 10 Edition. If you have the money to spare, this is an option.