You may have tried to open your old 256-height minecraft levels generated from the various 256-hieght and higher mods in the Minecraft 1.2 only to find minecraft crashing instantly. You might have then, like me, tried to open up your precious level in the testing version of MCedit only to be greeted with a message telling you there is no information in the level. Don’t worry, Your level is safe!
The new level converter does not overwrite your original file; however, it does rename the file type. You will need to go into your saves folder or wherever your level data are stored and look for the level.dat_mcr file. Change this file back to level.dat to replace the new, messed up one. Now your level will work again in MCedit Testing again.
Bringing your old 256-height Minecraft level into 1.2
With your old level loaded with MCedit, export any structure you want, or the entire level as a schematic file. If you haven’t dealt with schematic files, make a selection and you should see an option to export on the left (differs with versions of MCedit.) More info on MCedit can be found in the minecraft forums.
You’ll now need MCedit r1000 to import the schematic file into a 1.2 generated level. If you import an entire level, any new terrain will be generated from the new 1.2 code. MCedit r1000 can be found here:
or find the link to this page from the MCedit page on the minecraft forum.
I’ve posted the links to the testing version of MCedit in my last post: