hopefully fix #1120

FABRIC_CHANGELOG.txt

@@ -9,3 +9,4 @@ Change logging starts below:
 - fix schematic-printing deployers consuming double the resources they should (#1273)
 - fix invalid auto-shapeless recipes from appearing in EMI (#1148)
 - potential fix for a rare belt-related crash (#941)
+- potential fix for errors/crashes due to a missing locale (#1120)

src/main/java/com/simibubi/create/foundation/ClientResourceReloadListener.java

@@ -1,18 +1,24 @@
 package com.simibubi.create.foundation;
 
+import java.util.Collection;
+import java.util.Set;
+
 import com.simibubi.create.Create;
 import com.simibubi.create.CreateClient;
 import com.simibubi.create.content.kinetics.belt.BeltHelper;
 import com.simibubi.create.foundation.sound.SoundScapes;
 import com.simibubi.create.foundation.utility.LangNumberFormat;
 
 import net.fabricmc.fabric.api.resource.IdentifiableResourceReloadListener;
+import net.fabricmc.fabric.api.resource.ResourceReloadListenerKeys;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.ResourceManager;
 import net.minecraft.server.packs.resources.ResourceManagerReloadListener;
 
 public class ClientResourceReloadListener implements ResourceManagerReloadListener, IdentifiableResourceReloadListener {
 	public static final ResourceLocation ID = Create.asResource("client_reload_listener");
+	// fabric: make sure number format is updated after languages load
+	public static final Set<ResourceLocation> DEPENDENCIES = Set.of(ResourceReloadListenerKeys.LANGUAGES);
 
 	@Override
 	public void onResourceManagerReload(ResourceManager resourceManager) {
@@ -26,4 +32,9 @@ public void onResourceManagerReload(ResourceManager resourceManager) {
 	public ResourceLocation getFabricId() {
 		return ID;
 	}
+
+	@Override
+	public Collection<ResourceLocation> getFabricDependencies() {
+		return DEPENDENCIES;
+	}
 }

src/main/java/com/simibubi/create/foundation/utility/LangNumberFormat.java

@@ -4,6 +4,7 @@
 import java.util.Locale;
 
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.resources.language.LanguageInfo;
 import net.minecraft.util.Mth;
 
 public class LangNumberFormat {
@@ -16,10 +17,17 @@ public NumberFormat get() {
 	}
 
 	public void update() {
-		format = NumberFormat.getInstance(Minecraft.getInstance()
-			.getLanguageManager()
-			.getSelected()
-			.getJavaLocale());
+		LanguageInfo lang = Minecraft.getInstance()
+				.getLanguageManager()
+				.getSelected();
+		Locale locale = lang.getJavaLocale();
+
+		// fabric: clear error if this is somehow null.
+		if (locale == null) {
+			throw new IllegalStateException("LanguageInfo's javaLocale is null! info: " + lang);
+		}
+
+		format = NumberFormat.getInstance(locale);
 		format.setMaximumFractionDigits(2);
 		format.setMinimumFractionDigits(0);
 		format.setGroupingUsed(true);
@@ -33,4 +41,4 @@ public static String format(double d) {
 			.replace("\u00A0", " ");
 	}
 
-}
+}