I run a server on the latest snapshot, and when I updated from 1.14.3 pre-release 2 to pre-release 3, the console filled with errors and all of our item frames in the nether and overworld are gone.

Errors look like this:

• [WARNING] Exception loading entity:
• java.lang.NullPointerException: null
• at ati.f(SourceFile:86) ~[server.jar:?]
• at ath.c(SourceFile:232) ~[server.jar:?]
• at ail.<init>(SourceFile:234) ~[server.jar:?]
• at ath.<init>(SourceFile:35) ~[server.jar:?]
• at ati.<init>(SourceFile:46) ~[server.jar:?]
• at aip$$Lambda$626.00000000D10CB800.create(Unknown Source) ~[?:?]
• at aip.a(SourceFile:422) ~[server.jar:?]
• at aip.b(SourceFile:431) ~[server.jar:?]
• at aip$$Lambda$2333.0000000050456B10.apply(Unknown Source) ~[?:?]
• at java.util.Optional.map(Optional.java:215) ~[?:1.8.0_212]
• at aip.a(SourceFile:431) ~[server.jar:?]
• at aip.b(SourceFile:484) ~[server.jar:?]
• at aip.a(SourceFile:465) ~[server.jar:?]
• at bya.a(SourceFile:393) ~[server.jar:?]
• at bya.b(SourceFile:151) ~[server.jar:?]
• at bya$$Lambda$2218.00000000503D1640.accept(Unknown Source) ~[?:?]
• at bxo.w(SourceFile:484) ~[server.jar:?]
• at uu.a(SourceFile:594) ~[server.jar:?]
• at uu$$Lambda$2328.00000000504556C0.apply(Unknown Source) ~[?:?]
• at com.mojang.datafixers.util.Either.lambda$mapLeft$0(Either.java:162) ~[server.jar:?]
• at com.mojang.datafixers.util.Either$$Lambda$2282.000000005040FB50.apply(Unknown Source) ~[?:?]
• at com.mojang.datafixers.util.Either$Left.map(Either.java:38) ~[server.jar:?]
• at com.mojang.datafixers.util.Either.mapLeft(Either.java:162) ~[server.jar:?]
• at uu.a(SourceFile:583) ~[server.jar:?]
• at uu$$Lambda$2325.0000000050454500.apply(Unknown Source) ~[?:?]
• at java.util.concurrent.CompletableFuture.uniApply(CompletableFuture.java:602) ~[?:1.8.0_212]
• at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:577) ~[?:1.8.0_212]
• at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:442) ~[?:1.8.0_212]
• at uw.b(SourceFile:57) ~[server.jar:?]
• at uw$$Lambda$2205.00000000600645D0.run(Unknown Source) ~[?:?]
• at agq.e(SourceFile:83) [server.jar:?]
• at agq.a(SourceFile:123) [server.jar:?]
• at agq.run(SourceFile:91) [server.jar:?]
• at agn.h(SourceFile:135) [server.jar:?]
• at agn.p(SourceFile:114) [server.jar:?]
• at vg$a.p(SourceFile:506) [server.jar:?]
• at agn.c(SourceFile:123) [server.jar:?]
• at vg.a(SourceFile:123) [server.jar:?]
• at bhm.a(SourceFile:195) [server.jar:?]
• at bhp.a(SourceFile:106) [server.jar:?]
• at bhm.c(SourceFile:190) [server.jar:?]
• at bhm.e_(SourceFile:412) [server.jar:?]
• at bhy.a(SourceFile:103) [server.jar:?]
• at bhy.a(SourceFile:51) [server.jar:?]
• at vj.a(SourceFile:701) [server.jar:?]
• at ail.aW(SourceFile:1856) [server.jar:?]
• at ail.aa(SourceFile:411) [server.jar:?]
• at aiu.aa(SourceFile:288) [server.jar:?]
• at ail.h(SourceFile:390) [server.jar:?]
• at aiu.h(SourceFile:2046) [server.jar:?]
• at awb.h(SourceFile:262) [server.jar:?]
• at vj.i(SourceFile:388) [server.jar:?]
• at wa.b(SourceFile:196) [server.jar:?]
• at jb.a(SourceFile:243) [server.jar:?]
• at vz.c(SourceFile:171) [server.jar:?]
• at net.minecraft.server.MinecraftServer.b(SourceFile:836) [server.jar:?]
• at ui.b(SourceFile:343) [server.jar:?]
• at net.minecraft.server.MinecraftServer.a(SourceFile:763) [server.jar:?]
• at net.minecraft.server.MinecraftServer.run(SourceFile:631) [server.jar:?]
• at java.lang.Thread.run(Thread.java:813) [?:1.8.0_212]

Console log is attached.