diff --git a/BuildController.gd b/BuildController.gd
index 1266c18..aba4f36 100644
--- a/BuildController.gd
+++ b/BuildController.gd
@@ -148,7 +148,7 @@ var pending_time: float = 0.0
 
 func _ready() -> void:
 	build_button.pressed.connect(_on_build_pressed)
-	build_close_button.pressed.connect(func(): build_menu.visible = false)
+	build_close_button.pressed.connect(_close_build_menu)
 	build_mothership_button.pressed.connect(_on_place_mothership)
 	build_crafter_button.pressed.connect(_on_place_crafter)
 	build_command_button.pressed.connect(_on_place_command_center)
@@ -394,6 +394,14 @@ func _on_place_command_center() -> void:
 	_show_building_info(GameState.BUILDING_COMMAND_CENTER)
 
 
+func _close_build_menu() -> void:
+	# The popup is a child panel of this menu; leaving it "open" while its
+	# parent is hidden is what blocked every button in the game.
+	info_popup.visible = false
+	pending_build_type = ""
+	build_menu.visible = false
+
+
 func _on_place_ship_lab() -> void:
 	_show_building_info(GameState.BUILDING_SHIP_LAB)
 
diff --git a/IconButton.gd b/IconButton.gd
index 999e2fe..825cc9b 100644
--- a/IconButton.gd
+++ b/IconButton.gd
@@ -61,7 +61,13 @@ func _blocked_by_modal() -> bool:
 	# there. So the panels stay transparent to input and the buttons check
 	# instead.
 	for menu in get_tree().get_nodes_in_group("modal_menus"):
-		if menu.visible and not menu.is_ancestor_of(self):
+		# is_visible_in_tree(), NOT visible. Hiding a parent leaves the
+		# child's own `visible` flag true, and the build menu's info popup is
+		# itself a modal panel - so closing the build menu with the X left an
+		# invisible popup still claiming to be open, and every button in the
+		# game was blocked from then on. That is not a state a player can
+		# get out of.
+		if menu.is_visible_in_tree() and not menu.is_ancestor_of(self):
 			return true
 	return false
 
diff --git a/tests/test_modal_blocks_input.gd b/tests/test_modal_blocks_input.gd
index 19c3e78..2aca0a9 100644
--- a/tests/test_modal_blocks_input.gd
+++ b/tests/test_modal_blocks_input.gd
@@ -132,6 +132,30 @@ func _process(delta: float) -> bool:
 				quit(1)
 				return true
 			print("touch on the panel consumed, fleet target unchanged")
+
+			# --- 5. a hidden parent must not leave a panel "open" -------
+			# The build menu's info popup is itself a modal panel. Hiding the
+			# build menu leaves the popup's own `visible` flag true, so a
+			# guard testing `visible` rather than `is_visible_in_tree()`
+			# blocked EVERY button in the game from then on - with no way for
+			# a player to get out of it. Reported three times as "the buttons
+			# do nothing".
+			skill_menu.visible = false
+			var controller2: Node = scene.get_node("BuildController")
+			controller2._on_build_pressed()
+			controller2._show_building_info(GameState.BUILDING_SHIP_CRAFTER)
+			scene.get_node("UI/BuildMenu").visible = false
+			var info: Control = scene.get_node("UI/BuildMenu/InfoPopup")
+			print("popup after hiding its parent: visible=%s in_tree=%s" % [
+				info.visible, info.is_visible_in_tree()
+			])
+			outside_fired = false
+			_tap(map_button)
+			if not outside_fired:
+				print("TEST_MODAL_BLOCKS_INPUT: FAIL (a panel hidden with its parent still blocks every button)")
+				quit(1)
+				return true
+			print("hidden-with-parent panel no longer blocks anything")
 			print("TEST_MODAL_BLOCKS_INPUT: PASS")
 			quit(0)
 			return true