Get it to a point where it works minimally on 1.13 Spigot.

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/BundledBlockData.java

@@ -63,7 +63,7 @@ public class BundledBlockData {
     private BundledBlockData() {
         try {
             loadFromResource();
-        } catch (IOException e) {
+        } catch (Throwable e) {
             log.log(Level.WARNING, "Failed to load the built-in block registry", e);
         }
     }

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/BundledBlockRegistry.java

@@ -44,7 +44,7 @@ public class BundledBlockRegistry implements BlockRegistry {
     @Nullable
     @Override
     public BlockMaterial getMaterial(String id) {
-        return BundledBlockData.getInstance().getMaterialById(id);
+        return new PassthroughBlockMaterial(BundledBlockData.getInstance().getMaterialById(id));
     }
 
     @Nullable

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/BundledItemData.java

@@ -61,7 +61,7 @@ public class BundledItemData {
     private BundledItemData() {
         try {
             loadFromResource();
-        } catch (IOException e) {
+        } catch (Throwable e) {
             log.log(Level.WARNING, "Failed to load the built-in item registry", e);
         }
     }

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/LegacyMapper.java

@@ -57,7 +57,7 @@ public class LegacyMapper {
     private LegacyMapper() {
         try {
             loadFromResource();
-        } catch (IOException e) {
+        } catch (Throwable e) {
             log.log(Level.WARNING, "Failed to load the built-in legacy id registry", e);
         }
     }

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/PassthroughBlockMaterial.java

@@ -0,0 +1,249 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.registry;
+
+import com.sk89q.worldedit.blocks.BlockMaterial;
+
+import javax.annotation.Nullable;
+
+public class PassthroughBlockMaterial implements BlockMaterial {
+
+    @Nullable private final BlockMaterial blockMaterial;
+
+    public PassthroughBlockMaterial(@Nullable BlockMaterial material) {
+        this.blockMaterial = material;
+    }
+
+    @Override
+    public boolean isRenderedAsNormalBlock() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isRenderedAsNormalBlock();
+        }
+    }
+
+    @Override
+    public boolean isFullCube() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isFullCube();
+        }
+    }
+
+    @Override
+    public boolean isOpaque() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isOpaque();
+        }
+    }
+
+    @Override
+    public boolean isPowerSource() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isPowerSource();
+        }
+    }
+
+    @Override
+    public boolean isLiquid() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isLiquid();
+        }
+    }
+
+    @Override
+    public boolean isSolid() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isSolid();
+        }
+    }
+
+    @Override
+    public float getHardness() {
+        if (blockMaterial == null) {
+            return 0;
+        } else {
+            return blockMaterial.getHardness();
+        }
+    }
+
+    @Override
+    public float getResistance() {
+        if (blockMaterial == null) {
+            return 0;
+        } else {
+            return blockMaterial.getResistance();
+        }
+    }
+
+    @Override
+    public float getSlipperiness() {
+        if (blockMaterial == null) {
+            return 0;
+        } else {
+            return blockMaterial.getSlipperiness();
+        }
+    }
+
+    @Override
+    public boolean isGrassBlocking() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isGrassBlocking();
+        }
+    }
+
+    @Override
+    public float getAmbientOcclusionLightValue() {
+        if (blockMaterial == null) {
+            return 0;
+        } else {
+            return blockMaterial.getAmbientOcclusionLightValue();
+        }
+    }
+
+    @Override
+    public int getLightOpacity() {
+        if (blockMaterial == null) {
+            return 0;
+        } else {
+            return blockMaterial.getLightOpacity();
+        }
+    }
+
+    @Override
+    public int getLightValue() {
+        if (blockMaterial == null) {
+            return 0;
+        } else {
+            return blockMaterial.getLightValue();
+        }
+    }
+
+    @Override
+    public boolean isFragileWhenPushed() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isFragileWhenPushed();
+        }
+    }
+
+    @Override
+    public boolean isUnpushable() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isUnpushable();
+        }
+    }
+
+    @Override
+    public boolean isAdventureModeExempt() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isAdventureModeExempt();
+        }
+    }
+
+    @Override
+    public boolean isTicksRandomly() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isTicksRandomly();
+        }
+    }
+
+    @Override
+    public boolean isUsingNeighborLight() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isUsingNeighborLight();
+        }
+    }
+
+    @Override
+    public boolean isMovementBlocker() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isMovementBlocker();
+        }
+    }
+
+    @Override
+    public boolean isBurnable() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isOpaque();
+        }
+    }
+
+    @Override
+    public boolean isToolRequired() {
+        if (blockMaterial == null) {
+            return true;
+        } else {
+            return blockMaterial.isToolRequired();
+        }
+    }
+
+    @Override
+    public boolean isReplacedDuringPlacement() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.isReplacedDuringPlacement();
+        }
+    }
+
+    @Override
+    public boolean isTranslucent() {
+        if (blockMaterial == null) {
+            return !isOpaque();
+        } else {
+            return blockMaterial.isTranslucent();
+        }
+    }
+
+    @Override
+    public boolean hasContainer() {
+        if (blockMaterial == null) {
+            return false;
+        } else {
+            return blockMaterial.hasContainer();
+        }
+    }
+}