NBT does not use UTF-8, it's MUTF-8.

NBT uses MUTF-8, not UTF-8. Valid game-generated files will result in UnicodeDecodeErrors when using Twoolie’s NBT. Minimal reproduction file with an embedded MUTF-8 NULL: encoded.dat.gz

I’d normally send you a PR to use my MUTF-8 encoder, but being dependency-free seems to be a project goal. There’s a pure-python version in there you can just copy.

@1dt

[TkTech]

Since this library wants to be dependency free, and py2.7 compatible (which mutf8 is not), instead of a PR here’s a patch anyone stumbling on this with an unreadable file can use (as long as you’re py3):

diff --git a/nbt/nbt.py b/nbt/nbt.py
index 947a65e..8f633bd 100644
--- a/nbt/nbt.py
+++ b/nbt/nbt.py
@@ -4,12 +4,13 @@ Handle the NBT (Named Binary Tag) data format
 For more information about the NBT format:
 https://minecraft.gamepedia.com/NBT_format
 """
-
 from struct import Struct, error as StructError
 from gzip import GzipFile
 from collections import MutableMapping, MutableSequence, Sequence
 import sys

+import mutf8
+
 _PY3 = sys.version_info >= (3,)
 if _PY3:
     unicode = str
@@ -353,10 +354,10 @@ class TAG_String(TAG, Sequence):
         read = buffer.read(length.value)
         if len(read) != length.value:
             raise StructError()
-        self.value = read.decode("utf-8")
+        self.value = mutf8.decode_modified_utf8(read)

     def _render_buffer(self, buffer):
-        save_val = self.value.encode("utf-8")
+        save_val = mutf8.encode_modified_utf8(self.value)
         length = TAG_Short(len(save_val))
         length._render_buffer(buffer)
         buffer.write(save_val)
diff --git a/setup.py b/setup.py
index e6a7cd5..4338408 100755
--- a/setup.py
+++ b/setup.py
@@ -13,6 +13,7 @@ setup(
   license          = open("LICENSE.txt").read(),
   long_description = open("README.txt").read(),
   packages         = ['nbt'],
+  install_requires = ['mutf8'],
   classifiers      = [
         "Development Status :: 5 - Production/Stable",
         "Intended Audience :: Developers",

[Netherwhal]

Still getting the same issue though:

UnicodeDecodeError: ‘mutf-8’ codec can’t decode byte 0xed in position 630: 6-byte codepoint started, but input too short to finish.