diff --git a/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/bugfix/model_data_manager_cme/ModelDataManagerMixin.java b/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/bugfix/model_data_manager_cme/ModelDataManagerMixin.java
new file mode 100644
index 00000000..45836c89
--- /dev/null
+++ b/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/bugfix/model_data_manager_cme/ModelDataManagerMixin.java
@@ -0,0 +1,54 @@
+package org.embeddedt.modernfix.forge.mixin.bugfix.model_data_manager_cme;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraftforge.client.model.ModelDataManager;
+import org.embeddedt.modernfix.annotation.ClientOnlyMixin;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.ModifyArg;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import java.util.Collections;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Function;
+
+/**
+ * Fix several concurrency issues in the default ModelDataManager.
+ */
+@Mixin(ModelDataManager.class)
+@ClientOnlyMixin
+public abstract class ModelDataManagerMixin {
+    @Shadow protected static void refreshModelData(Level world, ChunkPos chunk) {
+        throw new AssertionError();
+    }
+
+    /**
+     * Make the set of positions to refresh a real concurrent hash set rather than relying on synchronizedSet,
+     * because the returned iterator won't be thread-safe otherwise. See https://github.com/AppliedEnergistics/Applied-Energistics-2/issues/7511
+     */
+    @ModifyArg(method = "requestModelDataRefresh", at = @At(value = "INVOKE", target = "Ljava/util/Map;computeIfAbsent(Ljava/lang/Object;Ljava/util/function/Function;)Ljava/lang/Object;", ordinal = 0), index = 1)
+    private static Function<ChunkPos, Set<BlockPos>> changeTypeOfSetUsed(Function<ChunkPos, Set<BlockPos>> mappingFunction) {
+        return pos -> Collections.newSetFromMap(new ConcurrentHashMap<>());
+    }
+
+    @Redirect(method = "getModelData(Lnet/minecraft/world/level/Level;Lnet/minecraft/world/level/ChunkPos;)Ljava/util/Map;", at = @At(value = "INVOKE", target = "Lnet/minecraftforge/client/model/ModelDataManager;refreshModelData(Lnet/minecraft/world/level/Level;Lnet/minecraft/world/level/ChunkPos;)V"))
+    private static void onlyRefreshOnMainThread(Level toUpdate, ChunkPos pos) {
+        // Only refresh model data on the main thread. This prevents calling getBlockEntity from worker threads
+        // which could cause weird CMEs or other behavior.
+        if(Minecraft.getInstance().isSameThread()) {
+            // Refresh the given chunk, and all its neighbors. This is less efficient than the default code
+            // but we have no choice since we need to not do refreshing on workers, and blocks might
+            // try to access model data in neighboring chunks.
+            for(int x = -1; x <= 1; x++) {
+                for(int z = -1; z <= 1; z++) {
+                    refreshModelData(toUpdate, new ChunkPos(pos.x + x, pos.z + z));
+                }
+            }
+        }
+    }
+}
diff --git a/settings.gradle b/settings.gradle
index c5b39d7c..514910c1 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -10,6 +10,8 @@ pluginManagement {
 include("test_agent")
 include("common")
 
+startParameter.excludedTaskNames.add(':fabric:testmod:genSources')
+
 def current_platforms = getProperty("enabled_platforms").tokenize(',')
 current_platforms.each { it ->
     def platform_name = it.trim()