Exception loading structure piece with id minecraft:nvi

Every so often i get the below spammed in the server console window, no reports of anything affected in game at this stage.

[06:29:47] [Server thread/ERROR]: Exception loading structure piece with id minecraft:nvi
java.lang.NullPointerException: null
at ccq.<init>(SourceFile:28) ~inecraft_server.19w41a.jar:?]
at ccq.a(SourceFile:53) ~inecraft_server.19w41a.jar:?]
at chs.<init>(SourceFile:44) ~inecraft_server.19w41a.jar:?]
at abf.a(SourceFile:18) ~inecraft_server.19w41a.jar:?]
at clb.<init>(SourceFile:48) ~inecraft_server.19w41a.jar:?]
at cfe$a.<init>(SourceFile:35) ~inecraft_server.19w41a.jar:?]
at clf.a(SourceFile:80) ~inecraft_server.19w41a.jar:?]
at cam.a(SourceFile:419) ~inecraft_server.19w41a.jar:?]
at cam.a(SourceFile:175) ~inecraft_server.19w41a.jar:?]
at wm.j(SourceFile:511) ~inecraft_server.19w41a.jar:?]
at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590) [?:1.8.0_181]
at aik.h(SourceFile:144) inecraft_server.19w41a.jar:?]
at aik.v(SourceFile:118) inecraft_server.19w41a.jar:?]
at wy$a.v(SourceFile:550) inecraft_server.19w41a.jar:?]
at wy.d(SourceFile:274) inecraft_server.19w41a.jar:?]
at net.minecraft.server.MinecraftServer.aZ(SourceFile:726) inecraft_server.19w41a.jar:?]
at net.minecraft.server.MinecraftServer.v(SourceFile:714) inecraft_server.19w41a.jar:?]
at aik.bj(SourceFile:103) inecraft_server.19w41a.jar:?]
at net.minecraft.server.MinecraftServer.u(SourceFile:698) inecraft_server.19w41a.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:654) inecraft_server.19w41a.jar:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]