--- a/net/minecraft/resources/RegistryDataLoader.java
+++ b/net/minecraft/resources/RegistryDataLoader.java
@@ -74,7 +74,7 @@
 
 public class RegistryDataLoader {
     private static final Logger LOGGER = LogUtils.getLogger();
-    private static final Comparator<ResourceKey<?>> ERROR_KEY_COMPARATOR = Comparator.comparing(ResourceKey::registry).thenComparing(ResourceKey::location);
+    private static final Comparator<ResourceKey<?>> ERROR_KEY_COMPARATOR = Comparator.<ResourceKey<?>, ResourceLocation>comparing(ResourceKey::registry).thenComparing(ResourceKey::location); // Paper - decompile fix
     private static final RegistrationInfo NETWORK_REGISTRATION_INFO = new RegistrationInfo(Optional.empty(), Lifecycle.experimental());
     private static final Function<Optional<KnownPack>, RegistrationInfo> REGISTRATION_INFO_CACHE = Util.memoize(knownPacks -> {
         Lifecycle lifecycle = knownPacks.map(KnownPack::isVanilla).map(vanilla -> Lifecycle.stable()).orElse(Lifecycle.experimental());
@@ -349,6 +349,7 @@
 
         RegistryDataLoader.Loader<T> create(Lifecycle lifecycle, Map<ResourceKey<?>, Exception> errors) {
             WritableRegistry<T> writableRegistry = new MappedRegistry<>(this.key, lifecycle);
+            io.papermc.paper.registry.PaperRegistryAccess.instance().registerRegistry(this.key, writableRegistry); // Paper - initialize API registry
             return new RegistryDataLoader.Loader<>(this, writableRegistry, errors);
         }