Changes to resource packs stop working after a couple reloads of a world.

Partner Rank: 2

Partner Team Reporting: Gamemode One

Verification builds: Minecraft.Windows_1.13.15.0_x64_UAP.Publish_Test, Minecraft.Windows_1.13.16.0_x64_UAP.Publish_Test

Summary:

Changes to resource packs stop working after a couple reloads of a world.

Impact:

Resource packs not loading consistently makes developing content nearly impossible.

Repro Steps:

This bug is a tricky one. It doesn't always reproduce in the same way. The most consistent way I've found is: 

1. Grab the default resource pack for 1.13.0.16 (Vanilla_Resource_Pack_Beta_1.13.0.16)
2. Make a noticeable change to the resource pack. Invalidating a texture is often enough.
3. Create a world with that pack active.
4. Close and reopen the world 3-4 times. Observe whether or not the changes you made are present.

Observed Results:

The changes made in the custom resource pack are not present when the world is loaded. The vanilla resource pack behavior takes over.

Expected Results:

The changes make in the custom resource are present consistently on worlds it is loaded on.

Screenshots/Videos attached: Yes/No

Notes about this video: The broken texture cows and swimming Alex are the intended result. I have removed the cow's texture path and the player's other animations as an easy way to demonstrate whether the pack is working or not. The vanilla behavior returning is the anomalous behavior. The content log errors are not related to the bug. I have reproduced this issue with animations that do not throw errors such as the "sneaking" animation.

https://youtu.be/OYd8XGGBSfw

Regression Builds: Minecraft.Windows_1.13.1.0_x64_UAP.Release_Test

Notes:

Changes to behavior packs seem to work as expected.
I have attached the pack used in the video in case it proves difficult to reproduce with other packs.