My World From 21w19a Doesn't Work On 21w20a

I tried to open my world from 21w19a in 21w20a, but i can't. Even though, it worked in 21w19a

Note :

• I Play In Minecraft Demo.

• I Am Using The Negative Time Using The Ant Venom's Technique

• I Add Two Datapack, The Latest Caves And Cliffs Preview Datapack (21w20a), And One Datapack That Worked In 21w19a.

• When I Press Safe Mode, It Doesn't Load.

• In The Datapack, There Are Some Template Pool, But Without The Structure

• The Datapack Is In The Attachment.

This Is The Game Output When I Tried To Open The World On 21w19a :

21:45:46.542
Ambiguity between arguments [teleport, location] and [teleport, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
21:45:46.547
Ambiguity between arguments [teleport, location] and [teleport, targets] with inputs: [0.1 -0.5 .9, 0 0 0]
21:45:46.558
Ambiguity between arguments [teleport, destination] and [teleport, targets] with inputs: [Player, 0123, @e, dd12be42-52a9-4a91-a8a1-11c01849e498]
21:45:46.562
Ambiguity between arguments [teleport, targets] and [teleport, destination] with inputs: [Player, 0123, dd12be42-52a9-4a91-a8a1-11c01849e498]
21:45:46.566
Ambiguity between arguments [teleport, targets, location] and [teleport, targets, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
21:45:46.574
Reloading ResourceManager: Default, CavesAndCliffsPreview.zip, Utility
21:45:49.050
Loaded 7 recipes
21:45:49.809
Loaded 1127 advancements
21:45:50.062
Pool element: Not a JSON object: null
21:45:50.794
Pool element: Not a JSON object: null
21:45:50.803
Pool element: Not a JSON object: null
21:45:50.817
Pool element: Not a JSON object: null; Not a valid resource location: minecraft:minecraft:tree/branchx_3 Non [a-z0-9/._-] character in path of location: minecraft:minecraft:tree/branchx_3; Not a valid resource location: minecraft:minecraft:tree/branchx_4 Non [a-z0-9/._-] character in path of location: minecraft:minecraft:tree/branchx_4

And This Is The Game Output When I Tried To Open The World On 21w20a :

21:30:21.976
Ambiguity between arguments [teleport, location] and [teleport, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
21:30:21.977
Ambiguity between arguments [teleport, location] and [teleport, targets] with inputs: [0.1 -0.5 .9, 0 0 0]
21:30:21.978
Ambiguity between arguments [teleport, destination] and [teleport, targets] with inputs: [Player, 0123, @e, dd12be42-52a9-4a91-a8a1-11c01849e498]
21:30:21.979
Ambiguity between arguments [teleport, targets] and [teleport, destination] with inputs: [Player, 0123, dd12be42-52a9-4a91-a8a1-11c01849e498]
21:30:21.980
Ambiguity between arguments [teleport, targets, location] and [teleport, targets, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
21:30:21.980
Reloading ResourceManager: Default, CavesAndCliffsPreview.zip, Utility
21:30:22.355
Loaded 7 recipes
21:30:22.395
Loaded 1127 advancements
21:30:22.435
Structure start: Not a JSON object: "minecraft:ruined_portal"; Not a JSON object: "minecraft:stronghold"; Not a JSON object: "minecraft:mineshaft"; Not a JSON object: "util:hall"
21:30:22.491
Structure start: Not a JSON object: "minecraft:ruined_portal"; Not a JSON object: "minecraft:stronghold"; Not a JSON object: "minecraft:mineshaft"; Not a JSON object: "minecraft:pillager_outpost"; Not a JSON object: "util:hall"
21:30:22.533
Failed to load datapacks, can't proceed with server load
com.google.gson.JsonParseException: Error loading registry data: Not a JSON object: null
	at gs.a(SourceFile:221)
	at java.base/java.util.Optional.ifPresent(Optional.java:178)
	at gs.a(SourceFile:221)
	at gs.a(SourceFile:212)
	at wo.a(SourceFile:57)
	at wo.a(SourceFile:51)
	at duy.a(SourceFile:1821)
	at duy.a(SourceFile:2050)
	at duy.a(SourceFile:1896)
	at duy.a(SourceFile:1836)
	at eae.a(SourceFile:174)
	at dwj.c(SourceFile:40)
	at dwd.a(SourceFile:16)
	at dwh.a(SourceFile:121)
	at dxg.a(SourceFile:27)
	at eae.a(SourceFile:311)
	at duz.b(SourceFile:94)
	at dzz.a(SourceFile:489)
	at duz.a(SourceFile:94)
	at duz.c(SourceFile:165)
	at aqe.execute(SourceFile:102)
	at duz.b(SourceFile:165)
	at org.lwjgl.glfw.GLFWMouseButtonCallbackI.callback(GLFWMouseButtonCallbackI.java:36)
	at org.lwjgl.system.JNI.invokeV(Native Method)
	at org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:3101)
	at com.mojang.blaze3d.systems.RenderSystem.flipFrame(SourceFile:172)
	at dpa.e(SourceFile:310)
	at duy.f(SourceFile:1130)
	at duy.e(SourceFile:721)
	at net.minecraft.client.main.Main.main(SourceFile:217)

I don't know why is this happening. Please fix this. I want to play my world on the latest snapshot.