Forum rules - please read before posting.
Tech questions during the weekend? Drop in on the community Discord channel!

After upgrading AC version, I have issue with Save/Load

a few days ago I upgraded AC from an older version to the latest. This because I'm still using Unity 4. After some script adaptation, things seems to go well. 
Things gone well except for the save/load function. When I save, quit the game, load that save, actions I perform, object I get and also inventory are not affected. Only the camera is correct...
I have this error after load and I don't know how to fix:

ArgumentException: The thing you want to instantiate is null.
UnityEngine.Object.CheckNullArgument (System.Object arg, System.String message) (at C:/buildslave/unity/build/artifacts/EditorGenerated/UnityEngineObject.cs:104)
UnityEngine.Object.Instantiate (UnityEngine.Object original) (at C:/buildslave/unity/build/artifacts/EditorGenerated/UnityEngineObject.cs:90)
AC.StateHandler.CreateSoundtrackEngine[Ambience] (System.String resourceName) (at Assets/AdventureCreator/Scripts/Game engine/StateHandler.cs:944)
AC.StateHandler.CreateAmbienceEngine () (at Assets/AdventureCreator/Scripts/Game engine/StateHandler.cs:937)
AC.StateHandler.LoadMainData (MainData mainData) (at Assets/AdventureCreator/Scripts/Game engine/StateHandler.cs:918)
AC.SaveSystem.ReturnMainData () (at Assets/AdventureCreator/Scripts/Save system/SaveSystem.cs:1258)
AC.SaveSystem._OnLevelWasLoaded () (at Assets/AdventureCreator/Scripts/Save system/SaveSystem.cs:582)
AC.SaveSystem.ReceiveDataToLoad (AC.SaveFile saveFile, System.String saveFileContents) (at Assets/AdventureCreator/Scripts/Save system/SaveSystem.cs:485)
AC.SaveFileHandler_SystemFile.Load (AC.SaveFile saveFile, Boolean doLog) (at Assets/AdventureCreator/Scripts/Save system/FileHandling/SaveFileHandler_SystemFile.cs:124)
AC.SaveSystem.LoadSaveGame (AC.SaveFile saveFile) (at Assets/AdventureCreator/Scripts/Save system/SaveSystem.cs:415)
AC.SaveSystem.LoadGame (Int32 elementSlot, Int32 saveID, Boolean useSaveID) (at Assets/AdventureCreator/Scripts/Save system/SaveSystem.cs:340)
AC.MenuSavesList.ProcessClick (AC.Menu _menu, Int32 _slot, MouseState _mouseState) (at Assets/AdventureCreator/Scripts/Menu/Menu classes/MenuSavesList.cs:700)
AC.PlayerMenus.CheckClick (AC.Menu _menu, AC.MenuElement _element, Int32 _slot, MouseState _mouseState) (at Assets/AdventureCreator/Scripts/Controls/PlayerMenus.cs:2163)
AC.PlayerMenus.CheckClicks (AC.Menu menu) (at Assets/AdventureCreator/Scripts/Controls/PlayerMenus.cs:1862)
AC.PlayerMenus.CheckForInput () (at Assets/AdventureCreator/Scripts/Controls/PlayerMenus.cs:1944)
AC.StateHandler.Update () (at Assets/AdventureCreator/Scripts/Game engine/StateHandler.cs:299)

Help is appreciated...
Thanks and bye


  • You will need to re-import AC in full from the Asset Store.  The error suggests you have no AmbienceEngine prefab in your AdventureCreator/Resources folder - is this the case?
  • Yes that's correct, there isn't the AmbenceEngine.prefab in that folder. But I cannot reimport all from the asset store because it says Unknown format when I try to import it...

    Error while importing package: Package has unknown format

    So I tried to copy from another project created with Unity 2017 but it hangs Unity 4. There is a possibility to have the package in Unity 4 compatible?

  • The official Unity 4 release has been sunset, but you should be able to recreate the necessary prefab yourself by comparing the one in your Unity 2017 project.

    In your Unity 2017 project, you should see that there's a prefab named AmbienceEngine that contains the Ambience and Audio Source components.  Remaking this from scratch in Unity 4, and placing it in the same directory in your Unity 4 project, should do the trick.  Depending on how far back you're upgrading from, you may also have to do the same thing for the MusicEngine prefab, and also make sure all the components on the GameEngine and PersistentEngine prefabs match between Unity versions.
  • Thanks for all your useful hint and suggestion Chris!
    Now I'm trying to convert the entire project in U2017 so I don't have other issue... I already fixed some of the errors (from other assets) and I noticed some things are changed also with AC (like the navmesh that I have to re-bake, the collision cylinder of the player (and I think of the others chars) I have to make smaller because now they run near the walls standing still) but I think I can handle easily those issue than the other issue caused by the old Unity version.
    And yes, the save/load systems back to work ^_^
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Welcome to the official forum for Adventure Creator.
Do NOT follow this link or you will be banned from the site!