pack manifest error makes some existing Minecraft maps unplayable

*Partner Team Reporting * Syclone Studios

Partner Rank 1

Verification builds and Platforms
v 1.19.30.25_rc1 build 11365957 on pc

Summary
The Mutant Survival map will download and install, but it has a pack manifest error.
(error message image below). The book and quilll at the start of the map which should initiate the map is just a book and quill

Impact
The map is unplayable as you cannot leave the pre-lobby

Steps to Reproduce
1. In current live store version of minecraft, choose and download Mutant Survival from the Minecraft store.
2. Leave all settings as they are.
3. Save Mutant Survival to a local save on the pc.
4. Uninstall live store version of minecraft.
5. Install dev release version 1.19.30.25_rc1
6. In settings, turn off Debug - Assertions break in the debugger to prevent minecraft from closing out.
7. Find local save of Mutant Survival on Pc and download it into minecraft.
8. Leave all settings as they are.
9. Click on Mutant Survival to enter into the map.
10. When error message appears, ok it until it disappers.
11. Map will open with player in pre-lobby.
12. Walk to the book at the front of the pre lobby and click on it to enter into the map.

Observed Results
Error message at the start of the map when you use release dev version, if you use publish version you just see that you cannot click on the book to start the map.

Expected Results
The book should tp the player into the map.

Regression Build
v1.19.22 build11239766 on pc

Notes
This issue seems to affect many other already existing maps also, Steampunk Inventores, Oakridge High, Tiki Island for example all have the same error message.