[MC-135147] Loading/saving structures with command blocks in them causes errors

My actions:
1) Saved any structure with redstone
2) At the same world, loaded same structure

Result: some parts of original structure are MISSING

Video proof: https://drive.google.com/file/d/14oNf80Kn_fYsRrUzmA2ql-Vv7v73R6yz/view?usp=sharing

[18:09:58] [Server thread/FATAL]: Error executing task
java.util.concurrent.ExecutionException: h: Exception while updating neighbours
	at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_171]
	at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_171]
	at k.a(SourceFile:200) [18w30b.jar:?]
	at net.minecraft.server.MinecraftServer.b(SourceFile:706) [18w30b.jar:?]
	at net.minecraft.server.MinecraftServer.a(SourceFile:661) [18w30b.jar:?]
	at dga.a(SourceFile:159) [18w30b.jar:?]
	at net.minecraft.server.MinecraftServer.run(SourceFile:564) [18w30b.jar:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_171]
Caused by: h: Exception while updating neighbours
	at axv.a(SourceFile:442) ~[18w30b.jar:?]
	at bdu.d(SourceFile:203) ~[18w30b.jar:?]
	at bdu.a(SourceFile:182) ~[18w30b.jar:?]
	at bkw.a(SourceFile:253) ~[18w30b.jar:?]
	at bnd.a(SourceFile:477) ~[18w30b.jar:?]
	at axv.a(SourceFile:269) ~[18w30b.jar:?]
	at bxj.a(SourceFile:239) ~[18w30b.jar:?]
	at bxj.b(SourceFile:179) ~[18w30b.jar:?]
	at bxj.a(SourceFile:175) ~[18w30b.jar:?]
	at bjz.c(SourceFile:420) ~[18w30b.jar:?]
	at bjz.r(SourceFile:378) ~[18w30b.jar:?]
	at ub.a(SourceFile:585) ~[18w30b.jar:?]
	at nn.a(SourceFile:107) ~[18w30b.jar:?]
	at nn.a(SourceFile:14) ~[18w30b.jar:?]
	at ix.a(SourceFile:10) ~[18w30b.jar:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_171]
	at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_171]
	at k.a(SourceFile:199) ~[18w30b.jar:?]
	... 5 more
Caused by: java.lang.NullPointerException
	at bjc.w(SourceFile:119) ~[18w30b.jar:?]
	at bjg.j(SourceFile:122) ~[18w30b.jar:?]
	at bdg.a(SourceFile:64) ~[18w30b.jar:?]
	at bkw.a(SourceFile:241) ~[18w30b.jar:?]
	at axv.a(SourceFile:427) ~[18w30b.jar:?]
	at bdu.d(SourceFile:203) ~[18w30b.jar:?]
	at bdu.a(SourceFile:182) ~[18w30b.jar:?]
	at bkw.a(SourceFile:253) ~[18w30b.jar:?]
	at bnd.a(SourceFile:477) ~[18w30b.jar:?]
	at axv.a(SourceFile:269) ~[18w30b.jar:?]
	at bxj.a(SourceFile:239) ~[18w30b.jar:?]
	at bxj.b(SourceFile:179) ~[18w30b.jar:?]
	at bxj.a(SourceFile:175) ~[18w30b.jar:?]
	at bjz.c(SourceFile:420) ~[18w30b.jar:?]
	at bjz.r(SourceFile:378) ~[18w30b.jar:?]
	at ub.a(SourceFile:585) ~[18w30b.jar:?]
	at nn.a(SourceFile:107) ~[18w30b.jar:?]
	at nn.a(SourceFile:14) ~[18w30b.jar:?]
	at ix.a(SourceFile:10) ~[18w30b.jar:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_171]
	at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_171]
	at k.a(SourceFile:199) ~[18w30b.jar:?]
	... 5 more