diff --git a/Utility Mods/FixBlockCategories/Data/Scripts/FixBlockCategories/MainSession.cs b/Utility Mods/FixBlockCategories/Data/Scripts/FixBlockCategories/MainSession.cs
new file mode 100644
index 000000000..779ef2413
--- /dev/null
+++ b/Utility Mods/FixBlockCategories/Data/Scripts/FixBlockCategories/MainSession.cs	
@@ -0,0 +1,76 @@
+using System;
+using Sandbox.Definitions;
+using System.Collections.Generic;
+using Sandbox.ModAPI;
+using VRage.Game.Components;
+using VRage.Network;
+using VRage.Utils;
+
+namespace SC.FixBlockCategories
+{
+    [MySessionComponentDescriptor(MyUpdateOrder.NoUpdate, int.MaxValue)] // load last
+    internal class MainSession : MySessionComponentBase
+    {
+        private HashSet<string> _nullSubtypes = new HashSet<string>();
+        private Dictionary<string, string> _subtypeToTypePairing = new Dictionary<string, string>();
+
+        public override void LoadData()
+        {
+            MyLog.Default.WriteLineAndConsole($"[FixBlockCategories] Start check...");
+
+            _subtypeToTypePairing = new Dictionary<string, string>();
+            foreach (var def in MyDefinitionManager.Static.GetAllDefinitions())
+            {
+                var blockdef = def as MyCubeBlockDefinition;
+                if (blockdef == null)
+                    continue;
+
+                if (string.IsNullOrEmpty(blockdef.Id.SubtypeName))
+                {
+                    _nullSubtypes.Add(blockdef.Id.TypeId.ToString().Replace("MyObjectBuilder_", ""));
+                    continue;
+                }
+
+                _subtypeToTypePairing[blockdef.Id.SubtypeName] = blockdef.Id.TypeId.ToString().Replace("MyObjectBuilder_", "");
+            }
+
+            foreach (var catdef in MyDefinitionManager.Static.GetCategories().Values)
+            {
+                MyLog.Default.WriteLineAndConsole($"[FixBlockCategories] CHK {catdef.Name}");
+                var replaced = new HashSet<string>();
+                foreach (var item in catdef.ItemIds)
+                {
+                    var name = FixItemName(catdef.Name, item);
+                    if (name != null)
+                        replaced.Add(name);
+                }
+                catdef.ItemIds = replaced;
+            }
+
+            MyLog.Default.WriteLineAndConsole($"[FixBlockCategories] Finished.");
+        }
+
+        private string FixItemName(string categoryName, string subtypeId)
+        {
+            // already valid
+            if (subtypeId.Contains("/"))
+                return subtypeId;
+
+            string typeId;
+            if (_subtypeToTypePairing.TryGetValue(subtypeId, out typeId)) // keen broke block category items with just subtypeid
+            {
+                MyLog.Default.WriteLineAndConsole($"[FixBlockCategories] Replaced {categoryName}::{typeId + "/" + subtypeId}");
+                return typeId + "/" + subtypeId;
+            }
+            else if (_nullSubtypes.Contains(subtypeId))
+            {
+                // subtype-less blocks (i.e. gravity generator)
+                MyLog.Default.WriteLineAndConsole($"[FixBlockCategories] Replaced {categoryName}::{subtypeId + "/(null)"}");
+                return subtypeId + "/(null)";
+            }
+
+            MyLog.Default.WriteLineAndConsole($"[FixBlockCategories] Removed {categoryName}::{subtypeId} (does the block exist?)");
+            return null;
+        }
+    }
+}
diff --git a/Utility Mods/FixBlockCategories/metadata.mod b/Utility Mods/FixBlockCategories/metadata.mod
new file mode 100644
index 000000000..83173346a
--- /dev/null
+++ b/Utility Mods/FixBlockCategories/metadata.mod	
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ModMetadata xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <ModVersion>1.0</ModVersion>
+</ModMetadata>
\ No newline at end of file
diff --git a/Utility Mods/FixBlockCategories/modinfo_main.sbmi b/Utility Mods/FixBlockCategories/modinfo_main.sbmi
new file mode 100644
index 000000000..0fa87a5a0
--- /dev/null
+++ b/Utility Mods/FixBlockCategories/modinfo_main.sbmi	
@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<MyObjectBuilder_ModInfo xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <SteamIDOwner>76561198274566684</SteamIDOwner>
+  <WorkshopId>0</WorkshopId>
+  <WorkshopIds>
+    <WorkshopId>
+      <Id>3473465973</Id>
+      <ServiceName>Steam</ServiceName>
+    </WorkshopId>
+  </WorkshopIds>
+</MyObjectBuilder_ModInfo>
\ No newline at end of file
diff --git a/Utility Mods/FixBlockCategories/thumb.jpg b/Utility Mods/FixBlockCategories/thumb.jpg
new file mode 100644
index 000000000..15e2d6a07
Binary files /dev/null and b/Utility Mods/FixBlockCategories/thumb.jpg differ