Basic utility for fixing old minecraft worlds that may have broken tile entities due to mods.
This fixes tile entites that contain upper case letters since minecraft now throws an exception loading these.
Intended to run on 1.13-1.16.5 worlds. May still work above 1.16.5.

usage: .\MinecraftNbtFixer.exe --world "path\to\world" --par 4
--world should be world root folder not region folder.
--par is count for parallel region processing. Higher values will use a lot more memory.