[MC-227945] "Exception loading structure piece" and "No key" error spam after upgrading a world to 1.17 and exploring chunks

Tons of these error messages appear in the console after upgrading my singleplayer world to 1.17 (by using the Optimize World option) and exploring/generating new chunks. I'm not entirely sure what the errors are about, but the new chunks I explored looked normal. ~~I also didn't encounter any game crashes or slowdown so I'm not sure if these errors are important or not.~~

EDIT (2021/06/09): These errors also come up in previously-generated chunks as well (all previously-generated chunks in my world are from 1.16.X), and do noticeably impact the performance (internal server TPS drops for a few seconds) when I encounter the error in pre-existing chunks.

I've attached the log file which shows all the errors that were outputted, however if the log file doesn't work or can't be viewed I pasted a few of the errors here:

[16:10:52] [Server thread/ERROR]: No key size in MapLike[{extra_size:2,min_size:1,type:"minecraft:column_placer"}]
[16:10:52] [Server thread/ERROR]: Exception loading structure piece with id minecraft:jigsaw
java.lang.IllegalStateException: Invalid pool element found
	at dbf.k(SourceFile:54) ~[minecraft-1.17-client.jar:?]
	at java.util.Optional.orElseThrow(Optional.java:403) ~[?:?]
	at dbf.<init>(SourceFile:54) ~[minecraft-1.17-client.jar:?]
	at cuc.a(SourceFile:151) ~[minecraft-1.17-client.jar:?]
	at cni.a(SourceFile:415) ~[minecraft-1.17-client.jar:?]
	at cni.a(SourceFile:175) ~[minecraft-1.17-client.jar:?]
	at abe.l(SourceFile:511) ~[minecraft-1.17-client.jar:?]
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1764) ~[?:?]
	at aqu.c(SourceFile:151) ~[minecraft-1.17-client.jar:?]
	at abp$a.c(SourceFile:527) ~[minecraft-1.17-client.jar:?]
	at aqu.z(SourceFile:125) ~[minecraft-1.17-client.jar:?]
	at abp$a.z(SourceFile:536) ~[minecraft-1.17-client.jar:?]
	at abp.d(SourceFile:279) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.bg(SourceFile:771) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.z(SourceFile:759) ~[minecraft-1.17-client.jar:?]
	at aqu.bq(SourceFile:110) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.y(SourceFile:743) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.x(SourceFile:696) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:274) ~[minecraft-1.17-client.jar:?]
	at java.lang.Thread.run(Thread.java:831) [?:?]

[16:11:24] [Server thread/ERROR]: No key dirt_provider in MapLike[{decorators:[],foliage_placer:{height:3,offset:0,radius:2,type:"minecraft:blob_foliage_placer"},heightmap:"OCEAN_FLOOR",ignore_vines:1b,leaves_provider:{state:{Name:"minecraft:oak_leaves",Properties:{distance:"7",persistent:"false"}},type:"minecraft:simple_state_provider"},max_water_depth:0,minimum_size:{limit:1,lower_size:0,type:"minecraft:two_layers_feature_size",upper_size:1},trunk_placer:{base_height:4,height_rand_a:2,height_rand_b:0,type:"minecraft:straight_trunk_placer"},trunk_provider:{state:{Name:"minecraft:oak_log",Properties:{axis:"y"}},type:"minecraft:simple_state_provider"}}]; No key sapling_provider in MapLike[{decorators:[],foliage_placer:{height:3,offset:0,radius:2,type:"minecraft:blob_foliage_placer"},heightmap:"OCEAN_FLOOR",ignore_vines:1b,leaves_provider:{state:{Name:"minecraft:oak_leaves",Properties:{distance:"7",persistent:"false"}},type:"minecraft:simple_state_provider"},max_water_depth:0,minimum_size:{limit:1,lower_size:0,type:"minecraft:two_layers_feature_size",upper_size:1},trunk_placer:{base_height:4,height_rand_a:2,height_rand_b:0,type:"minecraft:straight_trunk_placer"},trunk_provider:{state:{Name:"minecraft:oak_log",Properties:{axis:"y"}},type:"minecraft:simple_state_provider"}}]; No key foliage_provider in MapLike[{decorators:[],foliage_placer:{height:3,offset:0,radius:2,type:"minecraft:blob_foliage_placer"},heightmap:"OCEAN_FLOOR",ignore_vines:1b,leaves_provider:{state:{Name:"minecraft:oak_leaves",Properties:{distance:"7",persistent:"false"}},type:"minecraft:simple_state_provider"},max_water_depth:0,minimum_size:{limit:1,lower_size:0,type:"minecraft:two_layers_feature_size",upper_size:1},trunk_placer:{base_height:4,height_rand_a:2,height_rand_b:0,type:"minecraft:straight_trunk_placer"},trunk_provider:{state:{Name:"minecraft:oak_log",Properties:{axis:"y"}},type:"minecraft:simple_state_provider"}}]
[16:11:24] [Server thread/ERROR]: Exception loading structure piece with id minecraft:jigsaw
java.lang.IllegalStateException: Invalid pool element found
	at dbf.k(SourceFile:54) ~[minecraft-1.17-client.jar:?]
	at java.util.Optional.orElseThrow(Optional.java:403) ~[?:?]
	at dbf.<init>(SourceFile:54) ~[minecraft-1.17-client.jar:?]
	at cuc.a(SourceFile:151) ~[minecraft-1.17-client.jar:?]
	at cni.a(SourceFile:415) ~[minecraft-1.17-client.jar:?]
	at cni.a(SourceFile:175) ~[minecraft-1.17-client.jar:?]
	at abe.l(SourceFile:511) ~[minecraft-1.17-client.jar:?]
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1764) ~[?:?]
	at aqu.c(SourceFile:151) ~[minecraft-1.17-client.jar:?]
	at abp$a.c(SourceFile:527) ~[minecraft-1.17-client.jar:?]
	at aqu.z(SourceFile:125) ~[minecraft-1.17-client.jar:?]
	at abp$a.z(SourceFile:536) ~[minecraft-1.17-client.jar:?]
	at abp.d(SourceFile:279) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.bg(SourceFile:771) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.z(SourceFile:759) ~[minecraft-1.17-client.jar:?]
	at aqu.bq(SourceFile:110) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.y(SourceFile:743) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.x(SourceFile:696) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:274) ~[minecraft-1.17-client.jar:?]
	at java.lang.Thread.run(Thread.java:831) [?:?]

[16:12:21] [Server thread/ERROR]: No key dirt_provider in MapLike[{decorators:[],foliage_placer:{offset:{base:0,spread:2},radius:{base:2,spread:1},trunk_height:{base:1,spread:1},type:"minecraft:spruce_foliage_placer"},heightmap:"OCEAN_FLOOR",ignore_vines:1b,leaves_provider:{state:{Name:"minecraft:spruce_leaves",Properties:{distance:"7",persistent:"false"}},type:"minecraft:simple_state_provider"},max_water_depth:0,minimum_size:{limit:2,lower_size:0,type:"minecraft:two_layers_feature_size",upper_size:2},trunk_placer:{base_height:5,height_rand_a:2,height_rand_b:1,type:"minecraft:straight_trunk_placer"},trunk_provider:{state:{Name:"minecraft:spruce_log",Properties:{axis:"y"}},type:"minecraft:simple_state_provider"}}]; Input does not contain a key [type]: MapLike[{base:1,spread:1}]; Input does not contain a key [type]: MapLike[{base:0,spread:2}]; Input does not contain a key [type]: MapLike[{base:2,spread:1}]; No key sapling_provider in MapLike[{decorators:[],foliage_placer:{offset:{base:0,spread:2},radius:{base:2,spread:1},trunk_height:{base:1,spread:1},type:"minecraft:spruce_foliage_placer"},heightmap:"OCEAN_FLOOR",ignore_vines:1b,leaves_provider:{state:{Name:"minecraft:spruce_leaves",Properties:{distance:"7",persistent:"false"}},type:"minecraft:simple_state_provider"},max_water_depth:0,minimum_size:{limit:2,lower_size:0,type:"minecraft:two_layers_feature_size",upper_size:2},trunk_placer:{base_height:5,height_rand_a:2,height_rand_b:1,type:"minecraft:straight_trunk_placer"},trunk_provider:{state:{Name:"minecraft:spruce_log",Properties:{axis:"y"}},type:"minecraft:simple_state_provider"}}]; No key foliage_provider in MapLike[{decorators:[],foliage_placer:{offset:{base:0,spread:2},radius:{base:2,spread:1},trunk_height:{base:1,spread:1},type:"minecraft:spruce_foliage_placer"},heightmap:"OCEAN_FLOOR",ignore_vines:1b,leaves_provider:{state:{Name:"minecraft:spruce_leaves",Properties:{distance:"7",persistent:"false"}},type:"minecraft:simple_state_provider"},max_water_depth:0,minimum_size:{limit:2,lower_size:0,type:"minecraft:two_layers_feature_size",upper_size:2},trunk_placer:{base_height:5,height_rand_a:2,height_rand_b:1,type:"minecraft:straight_trunk_placer"},trunk_provider:{state:{Name:"minecraft:spruce_log",Properties:{axis:"y"}},type:"minecraft:simple_state_provider"}}]
[16:12:21] [Server thread/ERROR]: Exception loading structure piece with id minecraft:jigsaw
java.lang.IllegalStateException: Invalid pool element found
	at dbf.k(SourceFile:54) ~[minecraft-1.17-client.jar:?]
	at java.util.Optional.orElseThrow(Optional.java:403) ~[?:?]
	at dbf.<init>(SourceFile:54) ~[minecraft-1.17-client.jar:?]
	at cuc.a(SourceFile:151) ~[minecraft-1.17-client.jar:?]
	at cni.a(SourceFile:415) ~[minecraft-1.17-client.jar:?]
	at cni.a(SourceFile:175) ~[minecraft-1.17-client.jar:?]
	at abe.l(SourceFile:511) ~[minecraft-1.17-client.jar:?]
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1764) ~[?:?]
	at aqu.c(SourceFile:151) ~[minecraft-1.17-client.jar:?]
	at abp$a.c(SourceFile:527) ~[minecraft-1.17-client.jar:?]
	at aqu.z(SourceFile:125) ~[minecraft-1.17-client.jar:?]
	at abp$a.z(SourceFile:536) ~[minecraft-1.17-client.jar:?]
	at abp.d(SourceFile:279) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.bg(SourceFile:771) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.z(SourceFile:759) ~[minecraft-1.17-client.jar:?]
	at aqu.bq(SourceFile:110) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.y(SourceFile:743) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.x(SourceFile:696) ~[minecraft-1.17-client.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:274) ~[minecraft-1.17-client.jar:?]
	at java.lang.Thread.run(Thread.java:831) [?:?]