After hitting the lunch button or when I go to open a world my games crashes, taking me back to the launcher. Viewing the crash report I'm greeted with

// I let you down. Sorry

Time: 8/18/20 9:14 PM
Description: Exception ticking world

java.lang.ClassCastException: <unknown> cannot be cast to zr
at aae$$Lambda$4401/1784180981.accept(Unknown Source)
at java.util.ArrayList.forEach(ArrayList.java:1249)
at aae.p(SourceFile:368)
at aae.a(SourceFile:337)
at aag.a(SourceFile:348)
at net.minecraft.server.MinecraftServer.b(SourceFile:868)
at net.minecraft.server.MinecraftServer.a(SourceFile:808)
at emy.a(SourceFile:92)
at net.minecraft.server.MinecraftServer.w(SourceFile:667)
at net.minecraft.server.MinecraftServer.a(SourceFile:254)
at net.minecraft.server.MinecraftServer$$Lambda$4042/1925128083.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Thread: Server thread
Stacktrace:
at aae$$Lambda$4401/1784180981.accept(Unknown Source)
at java.util.ArrayList.forEach(ArrayList.java:1249)
at aae.p(SourceFile:368)
at aae.a(SourceFile:337)
at aag.a(SourceFile:348)

– Affected level –
Details:
All players: 1 total; [aah['Adamwasnothere2'/1914, l='ServerLevel[New World]', x=308.54, y=73.00, z=-197.11]]
Chunk stats: ServerChunkCache: 4262
Level dimension: minecraft:overworld
Level spawn location: World: (-128,64,160), Chunk: (at 0,4,0 in -8,10; contains blocks -128,0,160 to -113,255,175), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Level time: 3749 game time, 3749 day time
Level name: New World
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Level weather: Rain time: 39778 (now: false), thunder time: 136118 (now: false)
Known server brands: vanilla
Level was modded: false
Level storage version: 0x04ABD - Anvil
Stacktrace:
at net.minecraft.server.MinecraftServer.b(SourceFile:868)
at net.minecraft.server.MinecraftServer.a(SourceFile:808)
at emy.a(SourceFile:92)
at net.minecraft.server.MinecraftServer.w(SourceFile:667)
at net.minecraft.server.MinecraftServer.a(SourceFile:254)
at net.minecraft.server.MinecraftServer$$Lambda$4042/1925128083.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)

– System Details –
Details:
Minecraft Version: 1.16.2
Minecraft Version ID: 1.16.2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 4714325520 bytes (4495 MB) / 7583301632 bytes (7232 MB) up to 8589934592 bytes (8192 MB)
CPUs: 4
JVM Flags: 9 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx8G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
Player Count: 1 / 8; [aah['Adamwasnothere2'/1914, l='ServerLevel[New World]', x=308.54, y=73.00, z=-197.11]]
Data Packs: vanilla
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.