AssetBundle.LoadFromFile returns NULL

Hi,

I'm trying to load asset bundles on Android platform.
Everything goes fine on 99,9% devices, but there is small amount of devices, which gives me the error.
Devices: Samsung, Xiaomi, Huaiwei, motorola, etc.
OS: 4,5,6,7,8,9,10

I can't get the error on my test devices, so I am asking for help here.

Here's the logic of loading the AssetBundles:

First I am trying to load them async:

Code (CSharp):

1. IEnumerator LoadDatabasesAsync ()
2.     {
3.         AssetBundleCreateRequest bundleReq = AssetBundle.LoadFromFileAsync(
4. Path.Combine(Application.streamingAssetsPath, "androidBundles", "data"));
5.         yield return bundleReq;
6.  
7.         if (bundleReq == null)
8.         {
9.             LoadDataSync();
10.         } else
11.         {
12.             if (bundleReq.assetBundle == null)
13.             {
14.                 LoadDataSync();
15.             } else
16.             {
17.                 TextAsset textAsset = bundleReq.assetBundle.LoadAsset<TextAsset>("database");
18.                 // here textAsset = NULL, if I don't use above if statement to check request for NULL
19.                 bundleReq.assetBundle.Unload(false);
20.             }
21.         }
22.     }

If it fails, I am using sync method, just to quickly check AssetBundle for empty data:

Code (CSharp):

1. void LoadDataSync ()
2.     {
3.         string assetBundlesPath = Path.Combine(Application.streamingAssetsPath, "data");
4.         AssetBundle assetBundle = AssetBundle.LoadFromFile(assetBundlesPath);
5.         if (assetBundle == null) // So it gives NULL here
6.         {
7.             //I'm trying to change path code
8.             assetBundlesPath = "jar:file://" + Application.dataPath + "!/assets/androidBundles/data";
9.             assetBundle = AssetBundle.LoadFromFile(assetBundlesPath);
10.             if (assetBundle == null) // It gives NULL here
11.             {
12.                 //Just to test if the issue is with 2 "/" symbols
13.                 assetBundlesPath = "jar:file:///" + Application.dataPath + "!/assets/androidBundles/data";
14.                 assetBundle = AssetBundle.LoadFromFile(assetBundlesPath);
15.                 if (assetBundle == null) // It gives NULL here
16.                 {
17.                     //Don't know what's the problem
18.                 }
19.             }
20.         }
21.         TextAsset textAsset = assetBundle.LoadAsset<TextAsset>("database"); // here textAsset = NULL
22.     }

I am using Unity 2018.4.18f1, but the issue also happens on older versions.

 

Hi Aurimas, thank you for your answer.

- Yes, my assetbundles have no extension. Even the path(the first one and the others) gives me no such folder error.

- As I can see on unity site here: https://docs.unity3d.com/ru/current/Manual/StreamingAssets.html
The path should include "jar:file://" as I am using Application.dataPath. Also I can see the right representation of the path in logs.

The main trouble here is that I can not understand, why there are no assets in any case. I have right path, I even checked various path variants and there is nothing.
Can you give me advice on checking some other paths? Maybe if user have installed application on sd card, then moved it to phone storage or vice-versa, there can be any troubles in loading assets? Or maybe user couldn't somehow provide rights to store assetbundles on device? (on android 9 and 10?)