Index: ps/trunk/binaries/data/mods/public/gui/session/selection_details.js
===================================================================
--- ps/trunk/binaries/data/mods/public/gui/session/selection_details.js
+++ ps/trunk/binaries/data/mods/public/gui/session/selection_details.js
@@ -248,13 +248,13 @@
 		});
 	}
 	// And for number of workers
-	else if (entState.foundation && entState.visibility == "visible")
+	else if (entState.foundation && entState.visibility != "hidden")
 	{
 		Engine.GetGUIObjectByName("resourceCarryingIcon").hidden = false;
 		Engine.GetGUIObjectByName("resourceCarryingText").hidden = false;
 		Engine.GetGUIObjectByName("resourceCarryingIcon").sprite = "stretched:session/icons/repair.png";
 		Engine.GetGUIObjectByName("resourceCarryingText").caption = entState.foundation.numBuilders + "    ";
-		if (entState.foundation.numBuilders !== 0 && entState.buildTime)
+		if (entState.foundation.numBuilders !== 0 && entState.visibility == "visible" && entState.buildTime)
 			Engine.GetGUIObjectByName("resourceCarryingIcon").tooltip = sprintf(
 				translatePlural(
 					"Number of builders.\nTasking another to this foundation would speed construction up by %(speedup)s second.",
@@ -266,7 +266,7 @@
 		else
 			Engine.GetGUIObjectByName("resourceCarryingIcon").tooltip = translate("Number of builders.");
 	}
-	else if (entState.repairable && entState.repairable.numBuilders > 0 && entState.visibility == "visible")
+	else if (entState.repairable && entState.repairable.numBuilders > 0 && entState.visibility != "hidden")
 	{
 		Engine.GetGUIObjectByName("resourceCarryingIcon").hidden = false;
 		Engine.GetGUIObjectByName("resourceCarryingText").hidden = false;
Index: ps/trunk/binaries/data/mods/public/gui/session/unit_actions.js
===================================================================
--- ps/trunk/binaries/data/mods/public/gui/session/unit_actions.js
+++ ps/trunk/binaries/data/mods/public/gui/session/unit_actions.js
@@ -1521,6 +1521,8 @@
 	// (TODO: maybe we eventually want to look at more, and be more context-sensitive?
 	// e.g. prefer to attack an enemy unit, even if some friendly units are closer to the mouse)
 	let targetState = GetEntityState(target);
+	if (!targetState)
+		return { "possible": false };
 
 	// Check if any entities in the selection can do some of the available actions with target
 	for (let entityID of selection)
Index: ps/trunk/binaries/data/mods/public/simulation/components/Fogging.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/Fogging.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/Fogging.js
@@ -120,6 +120,10 @@
 	if (cmpFoundation)
 		cmpMirage.CopyFoundation(cmpFoundation);
 
+	var cmpRepairable = Engine.QueryInterface(this.entity, IID_Repairable);
+	if (cmpRepairable && !cmpFoundation)
+		cmpMirage.CopyRepairable(cmpRepairable);
+
 	var cmpHealth = Engine.QueryInterface(this.entity, IID_Health);
 	if (cmpHealth)
 		cmpMirage.CopyHealth(cmpHealth);
Index: ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
@@ -360,15 +360,21 @@
 			"progress": cmpFoundation.GetBuildPercentage(),
 			"numBuilders": cmpFoundation.GetNumBuilders()
 		};
-		ret.buildRate = cmpFoundation.GetBuildRate();
-		ret.buildTime = cmpFoundation.GetBuildTime();
+		cmpFoundation = Engine.QueryInterface(ent, IID_Foundation);
+		if (cmpFoundation)
+		{
+			ret.buildRate = cmpFoundation.GetBuildRate();
+			ret.buildTime = cmpFoundation.GetBuildTime();
+		}
 	}
 
 	let cmpRepairable = QueryMiragedInterface(ent, IID_Repairable);
 	if (cmpRepairable)
 	{
 		ret.repairable = { "numBuilders": cmpRepairable.GetNumBuilders() };
-		ret.repairRate = cmpRepairable.GetRepairRate();
+		cmpRepairable = Engine.QueryInterface(ent, IID_Repairable);
+		if (cmpRepairable)
+			ret.repairRate = cmpRepairable.GetRepairRate();
 	}
 
 	let cmpOwnership = Engine.QueryInterface(ent, IID_Ownership);
Index: ps/trunk/binaries/data/mods/public/simulation/components/Mirage.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/Mirage.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/Mirage.js
@@ -84,6 +84,14 @@
 Mirage.prototype.GetBuildPercentage = function() { return this.buildPercentage; };
 Mirage.prototype.GetNumBuilders = function() { return this.numBuilders; };
 
+// Repairable data (numBuilders shared with foundation as entities can't have both)
+
+Mirage.prototype.CopyRepairable = function(cmpRepairable)
+{
+	this.miragedIids.add(IID_Repairable);
+	this.numBuilders = cmpRepairable.GetNumBuilders();
+};
+
 // Health data
 
 Mirage.prototype.CopyHealth = function(cmpHealth)