[So I've been working on a Minecraft "Old" world since 2013, it's virtually the only world I ever play in, and after the new update 5/8 of it is gone. The edges of the world, which used to be at x=0 and 255 and z=0 and 255, are now at x=-64 and 191 and z=-128 and 127. I have no idea why it did this but it is incredibly annoying as I have lost years of work.
I uploaded a YouTube video to show what has happened to my world if you're interested:
Thank you for your report!
We're tracking this issue in MCPE-130640, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki