diff --git a/changelog/snippets/fix.6863md b/changelog/snippets/fix.6863md
new file mode 100644
index 00000000000..9b439084988
--- /dev/null
+++ b/changelog/snippets/fix.6863md
@@ -0,0 +1 @@
+- (#6863) Fix `OnAdjacentTo` error caused by dummy units attached to external factories and UEF engineering drones.
diff --git a/engine/Core/Categories.lua b/engine/Core/Categories.lua
index 4135b201199..d97dd2788dd 100644
--- a/engine/Core/Categories.lua
+++ b/engine/Core/Categories.lua
@@ -59,6 +59,7 @@ categories = {
     CANNOTUSEAIRSTAGING = categoryValue,
     CANTRANSPORTCOMMANDER = categoryValue,
     CAPTURE = categoryValue,
+    --- Changes engine behavior of units attached to this unit: Hides units and makes them unselectable.
     CARRIER = categoryValue,
     --- Allows the unit to land on water. Is introduced by https://github.com/FAForever/FA-Binary-Patches/pull/20
     CANLANDONWATER = categoryValue,
diff --git a/lua/sim/units/components/DebugUnitComponent.lua b/lua/sim/units/components/DebugUnitComponent.lua
index 6fa678e86a5..aee3d9887c8 100644
--- a/lua/sim/units/components/DebugUnitComponent.lua
+++ b/lua/sim/units/components/DebugUnitComponent.lua
@@ -22,6 +22,17 @@
 
 local DebugComponent = import("/lua/shared/components/debugcomponent.lua").DebugComponent
 
+---@type UnitState[]
+UnitStates = { 'Immobile', 'Moving', 'Attacking', 'Guarding', 'Building', 'Upgrading',
+    'WaitingForTransport', 'TransportLoading', 'TransportUnloading', 'MovingDown', 'MovingUp',
+    'Patrolling', 'Busy', 'Attached', 'BeingReclaimed', 'Repairing', 'Diving', 'Surfacing',
+    'Teleporting', 'Ferrying', 'WaitForFerry', 'AssistMoving', 'PathFinding', 'ProblemGettingToGoal',
+    'NeedToTerminateTask', 'Capturing', 'BeingCaptured', 'Reclaiming', 'AssistingCommander',
+    'Refueling', 'GuardBusy', 'ForceSpeedThrough', 'UnSelectable', 'DoNotTarget', 'LandingOnPlatform',
+    'CannotFindPlaceToLand', 'BeingUpgraded', 'Enhancing', 'BeingBuilt', 'NoReclaim', 'NoCost',
+    'BlockCommandQueue', 'MakingAttackRun', 'HoldingPattern', 'SiloBuildingAmmo',
+}
+
 ---@class DebugUnitComponent : DebugComponent
 DebugUnitComponent = Class(DebugComponent) {
 
@@ -118,4 +129,19 @@ DebugUnitComponent = Class(DebugComponent) {
         local blueprint = self.Blueprint
         DrawCircle(self:GetPosition(), math.max(blueprint.SizeX, blueprint.SizeY, blueprint.SizeZ), color)
     end,
+
+    DebugActiveStates = function(self)
+        if not self.EnabledLogging then
+            return
+        end
+
+        local activeStates = {}
+        for _, state in UnitStates do
+            if self:IsUnitState(state) then
+                table.insert(activeStates, state)
+            end
+        end
+
+        self:DebugLog('Active states: ' .. table.concat(activeStates, ', '))
+    end,
 }
diff --git a/lua/sim/units/uef/TConstructionPodUnit.lua b/lua/sim/units/uef/TConstructionPodUnit.lua
index 50633e90bdb..5333fcbc443 100644
--- a/lua/sim/units/uef/TConstructionPodUnit.lua
+++ b/lua/sim/units/uef/TConstructionPodUnit.lua
@@ -5,7 +5,6 @@ local oldGetGuards = TConstructionUnit.GetGuards
 ---@field Pod string
 ---@field Parent? UEL0301 | UEL0001 # Only these two units set the parent properly
 ---@field guardCache table
----@field guardDummy Unit
 ---@field rebuildDrone boolean # If true, the parent should rebuild the pod. Caches script bit 1.
 TConstructionPodUnit = ClassUnit(TConstructionUnit) {
     Parent = nil,
@@ -13,9 +12,6 @@ TConstructionPodUnit = ClassUnit(TConstructionUnit) {
     ---@param self TConstructionPodUnit
     OnCreate = function(self)
         TConstructionUnit.OnCreate(self)
-        self.guardDummy = CreateUnitHPR('ZXA0003', self:GetArmy(), 0,0,0,0,0,0)
-        self.guardDummy:AttachTo(self, -1)
-        self.Trash:Add(self.guardDummy)
     end,
 
     ---@param self TConstructionPodUnit
@@ -40,22 +36,11 @@ TConstructionPodUnit = ClassUnit(TConstructionUnit) {
     ---@param transport Unit
     ---@param bone number
     OnAttachedToTransport = function(self, transport, bone)
-        local guards = self:GetGuards()
-        IssueClearCommands(guards)
-        IssueGuard(guards, self.guardDummy)
+        -- Removing the state allows guards to keep assisting the drone
+        self:SetUnitState("Attached", false)
         TConstructionUnit.OnAttachedToTransport(self, transport, bone)
     end,
 
-    ---@param self TConstructionPodUnit
-    ---@param transport Unit
-    ---@param bone number
-    OnDetachedFromTransport = function(self, transport, bone)
-        TConstructionUnit.OnDetachedFromTransport(self, transport, bone)
-        local guards = self.guardDummy:GetGuards()
-        IssueClearCommands(guards)
-        IssueGuard(guards, self)
-    end,
-
     ---@param self TConstructionPodUnit
     ---@param parent UEL0301 | UEL0001 # Only these two implement the function `NotifyOfPodDeath`
     ---@param podName string
@@ -95,7 +80,7 @@ TConstructionPodUnit = ClassUnit(TConstructionUnit) {
     ---@param target Unit|Prop
     OnStopReclaim = function(self, target)
         TConstructionUnit.OnStopReclaim(self, target)
-        -- Check if we finished our reclaim task and clear our cached commaand if so
+        -- Check if we finished our reclaim task and clear our cached command if so
         if self.guardCache and table.empty(target) then
             self.guardCache = nil
         end
diff --git a/units/ZXA0002/ZXA0002_unit.bp b/units/ZXA0002/ZXA0002_unit.bp
index bf4d521d406..eb559a7a509 100644
--- a/units/ZXA0002/ZXA0002_unit.bp
+++ b/units/ZXA0002/ZXA0002_unit.bp
@@ -5,12 +5,13 @@ UnitBlueprint {
         'FACTORY',
         'CONSTRUCTION',
         'SELECTABLE',
-        'UNTARGETTABLE',
+        'UNTARGETABLE',
         'RALLYPOINT',
         'SORTCONSTRUCTION',
         'DRAGBUILD',
         'SHOWQUEUE',
-        'EXTERNALFACTORYUNIT'
+        'EXTERNALFACTORYUNIT',
+        'UNSPAWNABLE',
     },
     Defense = {
         Health = 100000,
diff --git a/units/ZXA0003/ZXA0003_script.lua b/units/ZXA0003/ZXA0003_script.lua
index 8f0583c7b04..a0f0b281a5d 100644
--- a/units/ZXA0003/ZXA0003_script.lua
+++ b/units/ZXA0003/ZXA0003_script.lua
@@ -24,17 +24,6 @@ local DummyUnit = import('/lua/sim/unit.lua').DummyUnit
 
 ---@class ZXA0003 : DummyUnit
 ZXA0003 = ClassUnit(DummyUnit) {
-
-    OnCreate = function (self)
-        self:HideBone(0, true)
-        -- do not allow the unit to be killed or to take damage
-        self.CanTakeDamage = false
-
-        -- do not allow the unit to be reclaimed or targeted by weapons
-        self:SetReclaimable(false)
-        self:SetDoNotTarget(true)
-    end,
-
     DetachFrom = function(self)
     end,
 }
diff --git a/units/ZXA0003/ZXA0003_unit.bp b/units/ZXA0003/ZXA0003_unit.bp
index 00877047646..af09eb475de 100644
--- a/units/ZXA0003/ZXA0003_unit.bp
+++ b/units/ZXA0003/ZXA0003_unit.bp
@@ -8,40 +8,12 @@ UnitBlueprint{
         "UNTARGETABLE",
         "CARRIER",
     },
-    Defense = {
-        Health = 30,
-        MaxHealth = 30,
-    },
-    Display = {
-        Mesh = {
-            IconFadeInZoom = 2000,
-            LODs = {
-                {
-                    ShaderName = 'Unit',
-                    MeshName = '/Units/UEA0001/UEA0001_lod0.scm',
-                    AlbedoName = '/Units/UEA0001/UEA0001_Albedo.dds',
-                    NormalsName = '/Units/UEA0001/UEA0001_normalsTS.dds',
-                    SpecularName = '/Units/UEA0001/UEA0001_SpecTeam.dds',
-                },
-            },
-        },
-        UniformScale = 0.12,
-    },
-    Economy = {
-        BuildCostEnergy = 0,
-        BuildCostMass = 0,
-        BuildTime = 0,
-    },
     General = {
         CapCost = 0,
-        Category = '',
-        SelectionPriority = 3,
     },
     Intel = { VisionRadius = 0 },
     Physics = {
         MotionType = "RULEUMT_None",
     },
-    SizeX = 0,
-    SizeY = 0,
-    SizeZ = 0,
+    CollisionShape = "None"
 }