How to convert my map to a new version?

Last time I uploaded and it worked here was 1.6.3, I think, and now we have 1.8.6. So it was like 2 years ago.

I come back, and I can't even play my world in minecraft because it simply does not want to load 90% of chunks.

I uploaded the map on minecraft world, and it won't even render

https://web.archive.org/web/2020/http://www.minecraftworldmap.com/worlds/xahVw

any help please? this is the reason why I stopped playing minecraft... such a simple game, and yet it is the most broken bug filled game I ever seen in my life. What a pity.

Does this mean that hundreds of hours I put on working on that map... gone to waste? maybe you guys got some sort of program that salvages a map.

thanks

The error email said "Anvil and MCRegion files found".

See https://web.archive.org/web/2020/http://www.minecraftworldmap.com/forum/s...hp?tid=398

And if skeight's instructions aren't clear enough, use mine:
1. Open the world folder.
2. Delete the level.dat_mcr if it exists.
3. Open the "region" folder.
4. Delete everything that ends in .mcr. Skip this step if none exist.
5. Back out of the "region" folder, open the "DIM1" folder, followed by the "region" folder in there.
6. Delete everything that ends in .mcr. Skip this step if none exist.
7. Back out by 2 folders, open the "DIM-1" folder, followed by the "region" folder in there.
8. Delete everything that ends in .mcr. Skip this step if none exist.
9. Upload the world again.
10. Enjoy your render.