diff -r b96ba3c1ab67 -r aed75d439027 qmlfrontend/main.cpp
--- a/qmlfrontend/main.cpp	Mon Apr 29 23:13:52 2019 +0200
+++ b/qmlfrontend/main.cpp	Mon Apr 29 23:41:25 2019 +0200
@@ -8,8 +8,6 @@
 #include "hwengine.h"
 #include "preview_acceptor.h"
 
-namespace Engine {};  // namespace Engine
-
 static QObject* previewacceptor_singletontype_provider(
     QQmlEngine* engine, QJSEngine* scriptEngine) {
   Q_UNUSED(scriptEngine)
@@ -24,6 +22,11 @@
 
   QQmlApplicationEngine engine;
 
+  qRegisterMetaType<EngineInstance::SimpleEventType>();
+  qRegisterMetaType<EngineInstance::LongEventType>();
+  qRegisterMetaType<EngineInstance::LongEventState>();
+  qRegisterMetaType<EngineInstance::PositionedEventType>();
+
   qmlRegisterSingletonType<PreviewAcceptor>(
       "Hedgewars.Engine", 1, 0, "PreviewAcceptor",
       previewacceptor_singletontype_provider);