How to remove legacy data?

I had a server contain some legacy data come from some plugin. Now, I don’t need that plugin anymore so I decide to remove it, but legacy data still remain and cause player can’t login to server.

Player lost connection when login:

[23:05:47] [Server thread/ERROR] [STDERR]: java.lang.RuntimeException: There was error attempting to update some data for the content updater:org.spongepowered.common.data.util.LegacyCustomDataClassContentUpdater
The original data is being returned, possibly causingissues later on, 
but the original data should not be lost. Please notify the developerof this exception with the stacktrace.
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.DataUpdaterDelegate.update(DataUpdaterDelegate.java:62)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.DataUpdaterDelegate.update(DataUpdaterDelegate.java:31)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.util.DataUtil.updateDataViewForDataManipulator(DataUtil.java:202)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.util.DataUtil.deserializeManipulatorList(DataUtil.java:157)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.item.ItemStack.readFromNbt(SourceFile:2283)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.item.ItemStack.handler$onRead$zge000(SourceFile:2116)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.item.ItemStack.<init>(SourceFile:139)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.entity.player.InventoryPlayer.func_70443_b(SourceFile:459)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.entity.player.EntityPlayer.func_70037_a(SourceFile:805)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.entity.player.EntityPlayerMP.func_70037_a(SourceFile:175)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.entity.Entity.func_70020_e(SourceFile:1516)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.world.storage.SaveHandler.func_75752_b(SourceFile:176)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.management.PlayerList.func_72380_a(SourceFile:283)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.management.PlayerList.initializeConnectionToPlayer(SourceFile:1214)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.management.PlayerList.func_72355_a(SourceFile:1173)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.network.NetHandlerLoginServer.func_147326_c(SourceFile:120)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.network.NetHandlerLoginServer.func_73660_a(SourceFile:66)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.network.NetworkManager.func_74428_b(SourceFile:232)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.network.NetworkSystem.func_151269_c(SourceFile:187)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.MinecraftServer.func_71190_q(SourceFile:1603)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(SourceFile:335)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.MinecraftServer.func_71217_p(SourceFile:562)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at net.minecraft.server.MinecraftServer.run(SourceFile:466)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at java.lang.Thread.run(Unknown Source)
[23:05:47] [Server thread/ERROR] [STDERR]: Caused by: org.spongepowered.api.data.DataRegistrationNotFoundException
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.util.LegacyCustomDataClassContentUpdater.lambda$update$0(LegacyCustomDataClassContentUpdater.java:51)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at java.util.Optional.orElseThrow(Unknown Source)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.util.LegacyCustomDataClassContentUpdater.update(LegacyCustomDataClassContentUpdater.java:51)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.util.LegacyCustomDataClassContentUpdater.update(LegacyCustomDataClassContentUpdater.java:33)
[23:05:47] [Server thread/ERROR] [STDERR]: 	at org.spongepowered.common.data.DataUpdaterDelegate.update(DataUpdaterDelegate.java:59)
[23:05:47] [Server thread/ERROR] [STDERR]: 	... 23 more
[23:05:47] [Server thread/WARN] [NetworkSystem]: Failed to handle packet for /127.0.0.1:54018
net.minecraft.util.ReportedException: Loading entity NBT
	at net.minecraft.entity.Entity.func_70020_e(SourceFile:1525) ~[sn.class:?]
	at net.minecraft.world.storage.SaveHandler.func_75752_b(SourceFile:176) ~[bbt.class:?]
	at net.minecraft.server.management.PlayerList.func_72380_a(SourceFile:283) ~[mt.class:?]
	at net.minecraft.server.management.PlayerList.initializeConnectionToPlayer(SourceFile:1214) ~[mt.class:?]
	at net.minecraft.server.management.PlayerList.func_72355_a(SourceFile:1173) ~[mt.class:?]
	at net.minecraft.server.network.NetHandlerLoginServer.func_147326_c(SourceFile:120) ~[mk.class:?]
	at net.minecraft.server.network.NetHandlerLoginServer.func_73660_a(SourceFile:66) ~[mk.class:?]
	at net.minecraft.network.NetworkManager.func_74428_b(SourceFile:232) ~[er.class:?]
	at net.minecraft.network.NetworkSystem.func_151269_c(SourceFile:187) [mh.class:?]
	at net.minecraft.server.MinecraftServer.func_71190_q(SourceFile:1603) [MinecraftServer.class:?]
	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(SourceFile:335) [lh.class:?]
	at net.minecraft.server.MinecraftServer.func_71217_p(SourceFile:562) [MinecraftServer.class:?]
	at net.minecraft.server.MinecraftServer.run(SourceFile:466) [MinecraftServer.class:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_71]
Caused by: java.util.NoSuchElementException: No value present
	at java.util.Optional.get(Unknown Source) ~[?:1.8.0_71]
	at org.spongepowered.common.data.util.DataUtil.deserializeManipulatorList(DataUtil.java:158) ~[DataUtil.class:1.11.2-6.1.0-BETA-5]
	at net.minecraft.item.ItemStack.readFromNbt(SourceFile:2283) ~[afj.class:?]
	at net.minecraft.item.ItemStack.handler$onRead$zge000(SourceFile:2116) ~[afj.class:?]
	at net.minecraft.item.ItemStack.<init>(SourceFile:139) ~[afj.class:?]
	at net.minecraft.entity.player.InventoryPlayer.func_70443_b(SourceFile:459) ~[aax.class:?]
	at net.minecraft.entity.player.EntityPlayer.func_70037_a(SourceFile:805) ~[aay.class:?]
	at net.minecraft.entity.player.EntityPlayerMP.func_70037_a(SourceFile:175) ~[ly.class:?]
	at net.minecraft.entity.Entity.func_70020_e(SourceFile:1516) ~[sn.class:?]
	... 13 more
[23:05:48] [Server thread/INFO] [NetHandlerLoginServer]: [email protected][***] (/127.0.0.1:54018) lost connection: Internal server error

Actually, this is my third post for similar question. xD

It looks like there is a corrupted itemstack in the player’s inventory. You might have to resort to something like an NBT editor for corrupted player items, or MCEdit for map objects. I experienced a similar issue recently with corrupted data on signs, and had to manually remove them from the map with MCEdit.

So, some of legacy CUSTOM data create by data API shall not cause this issue? Because of this kind data were spared everywhere already, I think manually remove them with NBT editor is inefficient.