Couldn't load chunk log spam

Step to reproduce
1. Download my map into your minecraft folder.
2. Fly into new area to generating map.
3. You will see error log

Couldn't load chunk

in your launcher.

Couldn't load chunk
java.lang.NullPointerException
	at brd.<init>(SourceFile:82)
	at bqd.e(SourceFile:302)
	at java.util.Map.computeIfAbsent(Unknown Source)
	at bqd.d(SourceFile:302)
	at bqd.a(SourceFile:287)
	at bqh.a(SourceFile:219)
	at uc.d(SourceFile:430)
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source)
	at java.util.ArrayList.forEach(Unknown Source)
	at uc.d(SourceFile:360)
	at net.minecraft.server.MinecraftServer.r(SourceFile:627)
	at net.minecraft.server.MinecraftServer.q(SourceFile:611)
	at net.minecraft.server.MinecraftServer.run(SourceFile:570)
	at java.lang.Thread.run(Unknown Source)