World Corrupt upon Entering End

Different from MC-116659 because end did not load at all. Crash immediate after entering portal.

1. Loaded existing world in local server.
2. Travel to previously used end portal
3. Enter portal.
4. Disconnected from local server.
5. Restart client and server (successful launch).
6. Attempt to join server.
7. Failed/Disconnected.

Client Crash log at step 7:
21:14:07 bhb Client thread Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at h.a(SourceFile:47)
at bhb.ax(SourceFile:956)
at bhb.a(SourceFile:404)
at net.minecraft.client.main.Main.main(SourceFile:123)
Caused by: java.lang.NullPointerException
at brc.a(SourceFile:581)
at iy.a(SourceFile:57)
at iy.a(SourceFile:10)
at he$1.run(SourceFile:13)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at h.a(SourceFile:46)
... 3 more
21:14:18 bjs Client thread Connecting to 127.0.0.1, 25565
21:14:26 bhb Client thread Stopping!

Server Crash log at step 7:
[21:14:20 WARN]: Failed to handle packet for /127.0.0.1:52375
f: Ticking player
at nu.k_(SourceFile:398) ~[minecraft_server.17w17a.jar:?]
at oe.G_(SourceFile:182) ~[minecraft_server.17w17a.jar:?]
at gf.a(SourceFile:231) ~[minecraft_server.17w17a.jar:?]
at od.c(SourceFile:187) [minecraft_server.17w17a.jar:?]
at net.minecraft.server.MinecraftServer.D(SourceFile:652) [minecraft_server.17w17a.jar:?]
at nd.D(SourceFile:335) [minecraft_server.17w17a.jar:?]
at net.minecraft.server.MinecraftServer.C(SourceFile:562) [minecraft_server.17w17a.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:466) [minecraft_server.17w17a.jar:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_71]
Caused by: java.lang.NullPointerException
at bau.a(SourceFile:188) ~[minecraft_server.17w17a.jar:?]
at bau.b(SourceFile:135) ~[minecraft_server.17w17a.jar:?]
at ayf.a(SourceFile:381) ~[minecraft_server.17w17a.jar:?]
at nr.a(SourceFile:227) ~[minecraft_server.17w17a.jar:?]
at am$b.a(SourceFile:118) ~[minecraft_server.17w17a.jar:?]
at am$a.a(SourceFile:148) ~[minecraft_server.17w17a.jar:?]
at am.a(SourceFile:85) ~[minecraft_server.17w17a.jar:?]
at nu.k_(SourceFile:390) ~[minecraft_server.17w17a.jar:?]
... 8 more
[21:14:20 INFO]: <player> lost connection: TextComponent{text='Internal server error', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}