Some Packs are missing or not applying correctly when uploading the world to Realms.

Partner Rank: 2
 
Partner Team Reporting: Builders Horizon
 
Verification Builds: Minecraft version 1.21.0, 1.21.1 on Windows 10, I-Phone 13, Xbox One
 
Regression Builds: Minecraft version 1.20.80 on Windows 10 (last known working version)
 
Summary: The packs are missing or not applying correctly when uploading the world to Realms, it's inconsistent and sometimes affects the scripting and behavior pack or and the resource pack.
 
Affects currently Live Content: Yes
 
Impact: This bug affects anybody who may want to play updated content. It prevents the proper application of resource packs and sometimes behavior packs when a world is uploaded to Realms, which could significantly impact user experience and lead to negative feedback.
 
Repro Steps:
1. Download and install the world template from ticket number #124042 into Minecraft.

2. Go to the World Create menu and create the world on Realms.

3. Join the newly created realm and notice that the resource pack isn't working properly while scripting is still functioning in the background or vice versa.

4. You may have to reload and rejoin the realm twice for the scripting to work. This is not a bug with our code, but a realm inconsistency, and it sometimes does not fix the issue and it gets stuck not applying both packs.

6. Attempt playing the world locally; it works fine with no issues. The problem only occurs on Realms from our testing.
 
Observed Results: The packs are missing or not applying correctly when the world is uploaded to Realms. The world fails to display the updated textures or run scripting in some cases. Players are not prompted to download the packs upon the first entrance to the realm. The behavior pack runs, but the resource pack does not, but this can sometimes be the other way around or both.
 
Expected Results: The packs should be applied correctly consistently, and the world should display the updated textures as it does when played locally and the scripting and behavior pack should work.
 
Screenshots/Videos attached: Yes

• Seek ticket Number from Greg Walls PM - ticket number #124042
   
  Notes:
• The issue only appears when the world is uploaded to Realms.

• The content works fine locally with no errors, indicating the problem is specific to Realms.

• The included videos, GIFs, screenshots, and world template file demonstrate the issue and the uploading process clearly.

• The issue started occurring after updating the textures in the resource pack and updating to the latest Minecraft version in the packs and world template level.dat file.

• Cert team tried multiple times to get it working on both PC and iPhone 13 with the same results.

• We also tried getting this working on Windows 10 and Xbox One devices with the exact same results reported in the fail/return report.

• Replication of the issue was possible by canceling the upload due to a network error?

• Upon the first realm open during the broken state, everything works fine except for the resources in some cases this doesn't always work.

• Players aren't receiving some of the packs when uploading templates onto Realms.

• After clearing the cache and re-importing the template, the issue persists.

• The scripts were not running when initially creating the realm with the template, but they worked after leaving and rejoining the same realm.

• The resource pack prompt appeared only on the second attempt.

• Content log errors indicate the issue is with loading the resource pack files?

• The problem did not exist before the update.

• The issue occurs in both versions 1.21.0 and 1.21.1

• Updated the manifest min engine version and incremented the version number in the manifest.json files for both the Resource and Behavior packs, but the issue persists.

• Realms have historically had issues around updates from our experience.