Bug (Case 1343820) Addressables doesn't detect corrupted local cached files prior loading

EDIT: https://issuetracker.unity3d.com/is...l-cached-files-are-not-detected-prior-loading

Using Unity 2019.4.20f1 and Addressables 1.18.4.

Addressables seems to be unable to detect if earlier downloaded files, cached files, are corrupted prior loading those files. I don't know if this functionality is broken or missing in Addressables. Searching the Addressables manual for "integrity" and "corrupt" doesn't yield any results.

Cached files can get corrupt for a variety of reasons. Therefore it's important that Addressables provides a mechanism to allow us to run an integrity/validation check in the player prior loading possibly corrupted data. This functionality is either not working or doesn't exist in Addressables.

Please see the attached video where I go over the problem in detail.

Reproduce

1. Open project on Windows
2. Open Build Settings and enable "Development Mode"
3. Open "Addressables Profiles" window and activate "Editor Hosted"
4. Open "Addressables Hosting" window and enable the "Local Hosting" service
5. Select "Assets/AddressableAssetsData/Menu" and set BuildPath=LocalBuildPath and LoadPath=LocalLoadPath in the Inspector
6. Click in the Addressables Groups window "Build > New Build > Default Build Script"
7. Press from main menu "File > Build" and build a Win64 Player
8. Select "Assets/AddressableAssetsData/Menu" and set BuildPath=RemoteBuildPath and LoadPath=RemoteLoadPath in the Inspector
9. Click in the Addressables Groups window "Build > New Build > Default Build Script"
10. Run the earlier built Player, press "Check for Catalog Update" and "Check for new Content" and notice it downloaded new content
11. Close Player, switch back to Unity
12. Open "Scenes/Menu.unity" and change the Main Camera background color
13. Click in the Addressables Groups window "Build > New Build > Default Build Script"
14. Run earlier built player
15. In the Player press "Check for Catalog Update"
16. In the Player press "Check for new Content"
17. In the Player press "Load" and notice the scene has the same color you just edited in Unity.
18. At this point you figured that content updates work
19. Close Player
20. In Windows Explorer delete the cached content in

    C:\Users\%UserName%\AppData\LocalLow\Unity\DefaultCompany_AddressablesCacheIntegrity

21. Run earlier built player
22. In the Player press "Check for Catalog Update". No update available, which is expected.
23. In the Player press "Check for new Content". New data is being downloaded, which is expected.
24. Close Player
25. Open the "__data" file located in a directory under

    C:\Users\%UserName%\AppData\LocalLow\Unity\DefaultCompany_AddressablesCacheIntegrity

    in a HexEditor and change it. This is to simulate a corrupted file.
26. Run earlier built player
27. In the Player press "Check for Catalog Update". No update available, which is expected.
28. In the Player press "Check for new Content". No update is available, which is NOT expected, because the local cached content is corrupt.

Actual
Addressables doesn't detect the corrupt cached content.

Expected
When asking Addressables for new content it detects if cached content is corrupt.
An API that we can use to run an integrity / validation step over the cached files and retrieving a list of corrupted files that we can redownload.


Notes

The catalog.json file is locally cached at:

C:\Users\%UserName%\AppData\LocalLow\DefaultCompany\AddressablesCacheIntegrity\com.unity.addressables

The downloaded content is locally cached at:

C:\Users\%UserName%\AppData\LocalLow\Unity\DefaultCompany_AddressablesCacheIntegrity

Deleting the cached content files allows the player to download them again.

 

This bug-report was closed as "By Design" with the following note:

It's against some vendor guidelines to just download data without the users consent, so this implementation is not acceptable from a guidelines point of view.

That's why I pointed out an API to run an integrity / validation step over the cached files is missing.

Here is an example how I would like to handle a corrupted bundle error:

1. Game detects corrupted assets during load
   
2. Game displays error "The game detected corrupted files that must be updated. We recommend that you're connected to Wi-Fi and have sufficient free space on your device."
3. Now the only option for the user is to press the "Update" button to continue playing. Without pressing "Update", the game does not download any data and does not continue.
   
4. Game runs an integrity / validation step over all cached files to collect a list of bundles that must be downloaded again. This functionality is missing in Addressables.
   
5. Game re-downloads corrupted data

Can you please re-open the bug-report?

 

We have not submitted to Apple yet but we have had the same concern when looking at the missing integrity/validation APIs. This is a game breaker for the Addressable system.

 

Has there been any update on that? A validation/integrity check API we can trigger ourselves is probably the best here...

 

Is there any workaround for this right now? @unity_shane

 

But this will also affect an user initiated download to fail without a retry when the connection gets shortly interrupted I assume?

 

@unity_shane Just curious. Is that Addressables 2.0 = dots Addressables?