diff --git a/source/app.d b/source/app.d
index de7d6a5..221ace0 100644
--- a/source/app.d
+++ b/source/app.d
@@ -37,7 +37,7 @@ int main(string[] args)
 
   const ret = loadFreeImage();
   if (ret == FISupport.noLibrary)
-    writeln("Couldn't load FreeImage!");
+    writeln("FreeImage 3.18 is required!");
 
   // start machine
   try
@@ -58,7 +58,7 @@ int main(string[] args)
   }
   catch (Exception e)
   {
-    writeln("no config!");
+    writeln("no config! creating default.");
     config = parseJSON("{}");
   }
   if (!("drives" in config))
diff --git a/source/machine.d b/source/machine.d
index a81ddb0..a23d839 100644
--- a/source/machine.d
+++ b/source/machine.d
@@ -26,7 +26,7 @@ import pixmap;
 import image_loader;
 import network;
 
-const VERSION = "0.9.0"; /// version of the software
+const VERSION = "0.9.1"; /// version of the software
 
 /**
   Class representing "the machine"!
@@ -61,7 +61,7 @@ class Machine
   this()
   {
     if (loadSDL() != sdlSupport)
-      throw new Exception("SDL not work! :(");
+      throw new Exception("SDL2 2.0.8 is required!");
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_JOYSTICK) != 0)
       throw new Exception(format("SDL_Init Error: %s", SDL_GetError()));
 
diff --git a/source/program.d b/source/program.d
index 84ad288..b68ea6c 100644
--- a/source/program.d
+++ b/source/program.d
@@ -68,9 +68,16 @@ class Program
     this.samples ~= null;
 
     // Load the Lua library.
-    dylib_load_lua();
-    this.lua = luaL_newstate();
-    luaL_openlibs(this.lua);
+    try
+    {
+      dylib_load_lua();
+      this.lua = luaL_newstate();
+      luaL_openlibs(this.lua);
+    }
+    catch (Throwable err)
+    {
+      writeln("Lua 5.3 is required!");
+    }
     registerFunctions(this);
     string luacode = this.machine.luaFilepathVars(this.filename) ~ readText(
         this.actualFile(this.filename));
diff --git a/system_drive/libs/class.lua b/system_drive/libs/class.lua
deleted file mode 100644
index 3c8df82..0000000
--- a/system_drive/libs/class.lua
+++ /dev/null
@@ -1,19 +0,0 @@
-print("Don't use class.lua.. object.lua is much better!")
-fs.delete(_DIR .. _FILE)
-
-local Class = {}
-
-function Class:new(super, constructor)
-  local class = setmetatable({}, super or {})
-  class.__index = class
-  if constructor then
-    class._new = constructor
-    function class:new(...)
-      local self = setmetatable({}, self)
-      self:_new(...)
-      return self
-    end
-  end
-  return class
-end
-return Class