added content error message screen on world creation

src/frontend/menu.cpp

@@ -280,10 +280,18 @@ void create_new_world_panel(Engine* engine, PagesControl* menu) {
         std::cout << "world seed: " << seed << std::endl;
 
         auto folder = paths->getWorldsFolder()/fs::u8path(nameutf8);
+
+        try {
+            engine->loadAllPacks();
+            engine->loadContent();
+        } catch (const std::runtime_error& error) {
+            guiutil::alert(engine->getGUI(),
+                        langs::get(L"Content Error", L"menu")+
+                        L": "+util::str2wstr_utf8(error.what()));
+            return;
+        }
         fs::create_directories(folder);
 
-        engine->loadAllPacks();
-        engine->loadContent();
         Level* level = World::create(
             nameutf8, folder, seed, 
             engine->getSettings(), 

src/logic/scripting/api_lua.cpp

@@ -14,13 +14,11 @@
 #include "../../lighting/Lighting.h"
 #include "../../logic/BlocksController.h"
 
-#if (LUA_VERSION_NUM < 502)
 inline void luaL_openlib(lua_State* L, const char* name, const luaL_Reg* libfuncs, int nup) {
     lua_newtable(L);
     luaL_setfuncs(L, libfuncs, nup);
     lua_setglobal(L, name);
 }
-#endif
 
 /* == world library ==*/
 static int l_world_get_day_time(lua_State* L) {