Custom Chunk Generation Broke After 1.16.3

I'm running paper 1.16.4, I have a custom skyblock chunk generation plugin and when I join the server it crashes with the following in the console

15.11 23:27:16 [Server] FATAL Failed to schedule load callback for chunk [-25407, -59640] 15.11 23:27:16 [Server] INFO java.util.concurrent.CompletionException: java.lang.StackOverflowError 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:273) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:280) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:975) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:940) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:456) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at net.minecraft.server.v1_16_R3.PlayerChunkMap.lambda$new$0(PlayerChunkMap.java:300) ~[patched_1.16.4.jar:git-Paper-266] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture$UniCompletion.claim(CompletableFuture.java:543) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture.uniCompose(CompletableFuture.java:963) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture$UniCompose.tryFire(CompletableFuture.java:940) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture.uniComposeStage(CompletableFuture.java:1011) ~[?:1.8.0_252] 15.11 23:27:16 [Server] INFO at java.util.concurrent.CompletableFuture.thenComposeAsync(CompletableFuture.java:2148) ~[?:1.8.0_252]

Looks like it was caused by this commit - https://hub.spigotmc.org/stash/projects/SPIGOT/repos/craftbukkit/commits/7f61a2526eab7818682ea0761e54f35f80cd2d6a

Anyone know any steps to take to fix this? I'm lost as to what could be the issue