Server can at least begin to launch now.

src/main/java/appeng/block/crafting/CraftingMonitorBlockRendering.java

@@ -1,28 +1,32 @@
 package appeng.block.crafting;
 
-import net.minecraft.client.renderer.RenderType;
-import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.api.distmarker.OnlyIn;
-
 import appeng.bootstrap.BlockRenderingCustomizer;
 import appeng.bootstrap.IBlockRendering;
 import appeng.bootstrap.IItemRendering;
 import appeng.client.render.crafting.MonitorBakedModel;
 import appeng.client.render.model.AutoRotatingBakedModel;
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.minecraft.client.render.RenderLayer;
+import net.minecraft.client.render.model.BakedModel;
+import net.minecraft.util.Identifier;
 
 public class CraftingMonitorBlockRendering extends BlockRenderingCustomizer {
 
     @Override
-    @OnlyIn(Dist.CLIENT)
+    @Environment(EnvType.CLIENT)
     public void customize(IBlockRendering rendering, IItemRendering itemRendering) {
-        rendering.renderType(RenderType.getCutout());
-        rendering.modelCustomizer((path, model) -> {
-            // The formed model handles rotations itself, the unformed one does not
-            if (model instanceof MonitorBakedModel) {
-                return model;
-            }
-            return new AutoRotatingBakedModel(model);
-        });
+        rendering.renderType(RenderLayer.getCutout());
+        rendering.modelCustomizer(CraftingMonitorBlockRendering::customizeModel);
+    }
+
+    @Environment(EnvType.CLIENT)
+    private static BakedModel customizeModel(Identifier path, BakedModel model) {
+        // The formed model handles rotations itself, the unformed one does not
+        if (model instanceof MonitorBakedModel) {
+            return model;
+        }
+        return new AutoRotatingBakedModel(model);
     }
 
 }