After flying with an elytra from my server's Enderman XP farm to the overworld portal, I glided down into the portal, only to be kicked from the server. I have not been able to log back on, even after restarting the server. Other accounts have been able to log on. Walking into the end portal appears to be fine. I have not attempted to recreate the bug for fear of losing another account. I receive the message "Internal Server Error"

The server console from when I attempt to log on is copied here:
20.04 22:55:51 [Server] Startup Done (2.559s)! For help, type "help" or "?"
20.04 22:55:51 [Server] Server thread/INFO Preparing spawn area: 53%
20.04 22:55:50 [Server] Server thread/INFO Preparing spawn area: 38%
20.04 22:55:49 [Server] Server thread/INFO Preparing start region for level 0
20.04 22:55:49 [Server] Server thread/INFO Loaded 463 advancements
20.04 22:55:49 [Server] Server thread/INFO Preparing level "Xilon_Kingdom"
20.04 22:55:49 [Server] Server thread/INFO Using epoll channel type
20.04 22:55:49 [Server] Server thread/INFO Starting Minecraft server on 209.182.104.85:25565
20.04 22:55:49 [Server] Server thread/INFO Generating keypair
20.04 22:55:49 [Server] Server thread/INFO Default game type: SURVIVAL
20.04 22:55:49 [Server] Server thread/INFO Loading properties
20.04 22:55:49 [Server] Server thread/INFO Starting minecraft server version 17w16a
20.04 22:55:46 [Server] INFO [CubedHost] Ready. Launching server!
20.04 22:55:46 [Server] INFO [CubedHost] Downloading files...
20.04 22:55:46 [Server] INFO [CubedHost] Installing "Minecraft Snapshot" version 17w16a
20.04 22:55:46 [Server] INFO [CubedHost] Overriding package version with user selection
20.04 22:55:46 [Server] INFO [CubedHost] An update for your server has been found
20.04 22:55:46 [Server] INFO [CubedHost] Preparing server
20.04 22:55:46 [Server] INFO [CubedHost] Automatic updates are enabled
20.04 22:55:46 [Server] INFO [CubedHost] Loading server configuration
20.04 22:55:46 [Server] INFO [CubedHost] Initializing server
20.04 22:55:46 [Server] INFO [CubedHost] Loading latest package information from CubedHost API
20.04 22:55:46 [Multicraft] Loaded config for "Minecraft: Snapshot 17w16a"
20.04 22:55:46 [Multicraft] Starting server!
20.04 22:55:46 [Multicraft] Loading server properties
20.04 22:55:46 [Multicraft] Server stopped
20.04 22:55:46 [Multicraft] Retrying server startup
20.04 22:55:41 [Multicraft] Server stopped
20.04 22:55:41 [Multicraft] Server shut down
20.04 22:55:40 [Server] Server Shutdown Thread/INFO Stopping server
20.04 22:55:40 [Server] Server thread/INFO Saving chunks for level 'Xilon_Kingdom'/The End
20.04 22:55:40 [Server] Server thread/INFO Saving chunks for level 'Xilon_Kingdom'/Nether
20.04 22:55:40 [Server] Server thread/INFO Saving chunks for level 'Xilon_Kingdom'/Overworld
20.04 22:55:40 [Server] Server thread/INFO Saving worlds
20.04 22:55:40 [Server] Server thread/WARN handleDisconnection() called twice
20.04 22:55:40 [Server] Server thread/INFO Saving players
20.04 22:55:40 [Server] Server thread/INFO Stopping server
20.04 22:55:40 [Server] Server thread/ERROR This crash report has been saved to: /./crash-reports/crash-2017-04-20_22.55.40-server.txt
20.04 22:55:40 [Server] INFO at java.lang.Thread.run(Thread.java:745) [?:1.8.0_91]
20.04 22:55:40 [Server] INFO at net.minecraft.server.MinecraftServer.run(SourceFile:466) [minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at net.minecraft.server.MinecraftServer.C(SourceFile:562) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at nb.D(SourceFile:335) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at net.minecraft.server.MinecraftServer.D(SourceFile:652) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ob.c(SourceFile:215) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at gd.l(SourceFile:379) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at oc.a(SourceFile:748) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at on.e(SourceFile:353) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at als.e(SourceFile:978) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ade.U(SourceFile:1275) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at afi.b(SourceFile:111) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at add.a(SourceFile:368) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at add.a(SourceFile:567) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at eq.get(SourceFile:40) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at java.util.Arrays$ArrayList.get(Arrays.java:3841) ~[?:1.8.0_91]
20.04 22:55:40 [Server] INFO java.lang.ArrayIndexOutOfBoundsException: -1
20.04 22:55:40 [Server] Server thread/ERROR Encountered an unexpected exception
20.04 22:55:40 [Server] Server thread/INFO MrGentleZombie left the game
20.04 22:55:40 [Disconnect] User MrGentleZombie has disconnected, reason: 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}}
20.04 22:55:40 [Server] INFO ... 8 more
20.04 22:55:40 [Server] INFO at ns.k_(SourceFile:324) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ade.B_(SourceFile:274) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at uq.B_(SourceFile:1728) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ade.n(SourceFile:515) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at uq.n(SourceFile:1902) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ade.a(SourceFile:1543) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at uq.a(SourceFile:1607) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at uh.a(SourceFile:835) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at uh.ad(SourceFile:897) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at apf.a(SourceFile:72) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ns.b(SourceFile:537) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at als.e(SourceFile:978) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ade.U(SourceFile:1275) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at afi.b(SourceFile:111) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at add.a(SourceFile:368) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at add.a(SourceFile:567) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at eq.get(SourceFile:40) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at java.util.Arrays$ArrayList.get(Arrays.java:3841) ~[?:1.8.0_91]
20.04 22:55:40 [Server] INFO Caused by: java.lang.ArrayIndexOutOfBoundsException: -1
20.04 22:55:40 [Server] INFO at java.lang.Thread.run(Thread.java:745) [?:1.8.0_91]
20.04 22:55:40 [Server] INFO at net.minecraft.server.MinecraftServer.run(SourceFile:466) [minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at net.minecraft.server.MinecraftServer.C(SourceFile:562) [minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at nb.D(SourceFile:335) [minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at net.minecraft.server.MinecraftServer.D(SourceFile:652) [minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ob.c(SourceFile:187) [minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at gd.a(SourceFile:231) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at oc.G_(SourceFile:182) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO at ns.k_(SourceFile:389) ~[minecraft_server.17w16a.jar:?]
20.04 22:55:40 [Server] INFO f: Colliding entity with block
20.04 22:55:40 [Server] Server thread/WARN Failed to handle packet for /173.20.38.194:59200
20.04 22:55:40 [Server] Server thread/INFO MrGentleZombie joined the game
20.04 22:55:40 [Multicraft] MrGentleZombie ran command Message of the Day
20.04 22:55:40 [Connect] User MrGentleZombie, IP 173.20.38.194
20.04 22:55:40 [Server] User Authenticator #1/INFO UUID of player MrGentleZombie is bd46cc41-eddc-4191-b582-e18fe50dbba0