diff --git a/src/ai/ai_gui.cpp b/src/ai/ai_gui.cpp
--- a/src/ai/ai_gui.cpp
+++ b/src/ai/ai_gui.cpp
@@ -182,8 +182,14 @@ struct AIListWindow : public Window {
 		nwi->widget_data = (this->vscroll->GetCapacity() << MAT_ROW_START) + (1 << MAT_COL_START);
 	}
 
-	virtual void OnInvalidateData(int data)
+	/**
+	 * Some data on this window has become invalid.
+	 * @param data Information about the changed data.
+	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
+	 */
+	virtual void OnInvalidateData(int data = 0, bool gui_scope = true)
 	{
+		if (!gui_scope) return;
 		if (_game_mode == GM_NORMAL && Company::IsValidID(this->slot)) {
 			delete this;
 			return;
@@ -437,8 +443,14 @@ struct AISettingsWindow : public Window 
 		}
 	}
 
-	virtual void OnInvalidateData(int data)
+	/**
+	 * Some data on this window has become invalid.
+	 * @param data Information about the changed data.
+	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
+	 */
+	virtual void OnInvalidateData(int data = 0, bool gui_scope = true)
 	{
+		if (!gui_scope) return;
 		if (_game_mode == GM_NORMAL && Company::IsValidID(this->slot)) delete this;
 	}
 };
@@ -692,8 +704,14 @@ struct AIConfigWindow : public Window {
 		}
 	}
 
-	virtual void OnInvalidateData(int data)
+	/**
+	 * Some data on this window has become invalid.
+	 * @param data Information about the changed data.
+	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
+	 */
+	virtual void OnInvalidateData(int data = 0, bool gui_scope = true)
 	{
+		if (!gui_scope) return;
 		if (!IsEditable(this->selected_slot)) {
 			this->selected_slot = INVALID_COMPANY;
 		}
@@ -1032,8 +1050,14 @@ struct AIDebugWindow : public QueryStrin
 		return state;
 	}
 
-	virtual void OnInvalidateData(int data = 0)
+	/**
+	 * Some data on this window has become invalid.
+	 * @param data Information about the changed data.
+	 * @param gui_scope Whether the call is done from GUI scope. You may not do everything when not in GUI scope. See #InvalidateWindowData() for details.
+	 */
+	virtual void OnInvalidateData(int data = 0, bool gui_scope = true)
 	{
+		if (!gui_scope) return;
 		if (data == -1 || ai_debug_company == data) this->SetDirty();
 
 		if (data == -2) {