Missing Scripts on loading Scene Asset Bundle

Hello Everyone,
I am developing a Unity loader which loads different scene on demand using asset Bundle. The Scene from the asset bundle loads correctly but the scripts attached to the object in the Scene doesn't load and show a warning message "The referenced script (Unknown) on this Behaviour is missing!". Can someone advise a solution to this problem?

 

Hi,
When creating an asset bundle, the code does not make it into the bundle. To import the code also, you can load them seperately as TextAssets.

see:
https://docs.unity3d.com/540/Documentation/Manual/scriptsinassetbundles.html
https://answers.unity.com/questions/1214408/how-to-import-script-at-run-time-using-assetbundle.html

 

Thanks.
Can you please explain where should I write the code to import another code at runtime, whether It should be inside an asset bundle or in the loader loading the scene asset bundle?

 

it can't be in the assetbundle you want to import/load, because you'd need to import and load it in order to do that The assetbundle is only a package that contains some data: it won't become meaningfull until you actually import it and load it's contents.

So you'll probably want to put both the import and load functionality in a scene, which will then know what to do with the content of the assetbundle (load code and then load objects/scene and whatever).

 

I had already tried that. Here is the code snippet. Can you please check were I am going wrong.

Code (CSharp):

1.  IEnumerator AssetUrl0(string url) {
2.        
3.         if (!assetBundle0)
4.         {
5.             Assembly assembly = Assembly.LoadFile(assemblyURL);
6.             GameObject gameObject = new GameObject();
7.             System.Type type = assembly.GetType("Rotation");
8.             gameObject.AddComponent(type);
9.  
10.             using (WWW www = new WWW(url))
11.             {
12.                 yield return www;
13.                 if (!string.IsNullOrEmpty(www.error))
14.                 {
15.                     Debug.LogError(www.error);
16.                     yield break;
17.                 }
18.                 assetBundle0 = www.assetBundle;
19.             }
20.          
21.             string[] scenes = assetBundle0.GetAllScenePaths();
22.  
23.             foreach (string scenepath in scenes)
24.             {
25.                 scene0 = Path.GetFileNameWithoutExtension(scenepath);              
26.                 SceneManager.LoadSceneAsync(scene0, LoadSceneMode.Additive);
27.  
28.                 //assetBundle.Unload(false);
29.                 //SceneManager.UnloadSceneAsync(scene);
30.             }
31.         }

 

Hmm, loading the scenes (line 21 onward) seems to be right, though you'll get an error if for whatever reason your www request goes wrong.

I don't think you're actually getting the code from an assetbundle, but you already have a dll ready at some address? I know I've been struggling a bit with the Assembly loading and found the advice to always try and use the 'Load' function like so:

var name = AssemblyName.GetAssemblyName(filepath);
var assembly = Assembly.Load(name);

Also note that when trying to load an assembly that is already loaded (or shares a name with an already loaded assembly) then you will just get the original returned.

 

I am not getting any code from the asset bundle because all the scripts go missing so I am loading the dll from some address. It fetches the dll correctly and game object is attached with the code inside dll but that object is of the main scene whereas I wanted to add the script to asset bundle scene or object.

 

Is the name of your imported dll 'Assembly-CSharp'? If it is, then when it tries to import, it will already see an assembly with the same name and not load this new one. You'll need to use assembly definitions to put your code in a different assembly, so you can load it.

 

I have a Rotation.cs script attached to gameobject in asset bundle scene and converted the same script to Rotation.dll. So do you mean I should change the name of the dll?

 

just changing the name of the ddl won't change the assembly name and it's the assembly name that is recognized. Take a look at this:
https://docs.unity3d.com/Manual/ScriptCompilationAssemblyDefinitionFiles.html

 

I think you are getting confused. I have made Rotaion.dll in the visual studio not just changing the name of dll

 

Hmm, can you post the Rotation class? Is it part of a Unity project or did you make it in a seperate visual studio solution which you built?

 

Do you have any news about that backport? I'm on a stable release and I don't want to bump to 2019.1 beta for that fix. I have tested it in 2018.3.4f1 and it's still broken.

 

Could it be that with this bug it was still possible to run it in Editor mode but not in a Standalone Build? Because that is exactly the problem that I encountered with assetbundles including prefabs referencing a DLL (some script references were still found though). When could we expect a backport to 2018.3?

So glad I found this post. This issue could make me research DLL stuff forever.

 

I tested in 2018.3.5 and verified it works now. Thanks Unity!

 

Is this currently working in 2019.1.10 and beyond? I am loading a dll in the same manner but still running into OPs issue.

 

Good question. Trying this in Unity 2019.3.0f1 and experiencing this problem.

Edit: Okay, I solved my problem with creating an Assembly Definition file for my scripts (which were previously generated into the Assembly-CSharp.dll. Yes, I renamed the dll (fullname) before creating the assetbundle for it). With the generated dll from the assembly definition file, it works now. Don't know why it doesn't work with the Assembly-CSharp.dll though, but maybe this is of help for some others too.