Workaround
Start Minecraft and start playing a Singleplayer game.
Disconnect to return to main menu
Join Multiplayer game
– This comment by @unknown
18w08b\: [^crash-2018-02-22_18.07.29-client.txt]
Description: Tesselating block in world
java.lang.NullPointerException: Tesselating block in world
at vo$a.a(SourceFile:77)
at vo$a.a(SourceFile:63)
at aye.a(SourceFile:210)
at bgg.a(SourceFile:263)
at clz.a(SourceFile:85)
at cly.a(SourceFile:65)
at coc.b(SourceFile:180)
at cny.a(SourceFile:100)
at cnx.b(SourceFile:141)
at clk.a(SourceFile:923)
at cle.b(SourceFile:1161)
at cle.a(SourceFile:1096)
at cle.a(SourceFile:957)
at bya.b(SourceFile:820)
at bya.a(SourceFile:381)
at net.minecraft.client.main.Main.main(SourceFile:141)
Linked issues
is duplicated by 43
Attachments
Comments 15
Possible Workaround: I have this bug every time I try to join a multiplayer server in 18w07b. However I can join without crashing in the following way:
Start Minecraft and start playing a Singleplayer game.
Disconnect to Return to main menu
Join Multiplayer game
This workaround worked..... even after I stopped the server and started it, I could log in normally...
I resetted my computer to see if Minecraft still logs normally when I was on the server, but unfortunately, it crashed again...
This is maybe useful info....
Glad to help...
---- Minecraft Crash Report ----
// Everything's going to plan. No, really, that was supposed to happen.
Time: 15-2-18 22:36
Description: Unexpected error
java.lang.NullPointerException: Unexpected error
at vn$a.a(SourceFile:77)
at vn$a.a(SourceFile:63)
at axq.a(SourceFile:210)
at bfs.a(SourceFile:263)
at abd.a(SourceFile:1105)
at ckd.b(SourceFile:1183)
at ckd.a(SourceFile:1083)
at ckd.a(SourceFile:944)
at bxe.b(SourceFile:820)
at bxe.a(SourceFile:381)
at net.minecraft.client.main.Main.main(SourceFile:141)
A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------
-- Head --
Thread: Client thread
Stacktrace:
at vn$a.a(SourceFile:77)
at vn$a.a(SourceFile:63)
at axq.a(SourceFile:210)
at bfs.a(SourceFile:263)
at abd.a(SourceFile:1105)
at ckd.b(SourceFile:1183)
at ckd.a(SourceFile:1083)
-- Affected level --
Details:
Level name: MpServer
All players: 1 total; [cjq['Mr_Killer01'/7112, l='MpServer', x=8,50, y=65,00, z=8,50]]
Chunk stats: MultiplayerChunkCache: 0, 0
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 1 game time, 1 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
Forced entities: 1 total; [cjq['Mr_Killer01'/7112, l='MpServer', x=8,50, y=65,00, z=8,50]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Non-integrated multiplayer server
Stacktrace:
at chn.a(SourceFile:368)
at bxe.b(SourceFile:1827)
at bxe.a(SourceFile:394)
at net.minecraft.client.main.Main.main(SourceFile:141)
-- System Details --
Details:
Minecraft Version: 18w07b
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 124922816 bytes (119 MB) / 301989888 bytes (288 MB) up to 1073741824 bytes (1024 MB)
JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=16M
Launched Version: 18w07b
LWJGL: 3.1.2 build 29
OpenGL: AMD Radeon HD 6300M Series GL version 4.5.13417 Compatibility Profile Context 15.301.1901.0, ATI Technologies Inc.
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.
Using VBOs: No
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs:
Current Language: English (United Kingdom)
Profiler Position: N/A (disabled)
CPU: 4x Intel(R) Core(TM) i3 CPU M 380 @ 2.53GHz

Same bug, but the crash report refuses to open for me. The content of the snapshot is well worth the bugs.
I couldn't click on "View crash report" when the crash happened in 18w08a already, but in 18w08b none of both client logs (when I try to login with a 2nd account into an Open to LAN world opened by account 1) throw an error this time; but on one log (main/1st hosting account) it says: "[PLAYERNAME] lost connection: Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host".
Thanks for the workaround, I also have this issue,
I tested and this issue is fixed in snapshot 18w09a.
Multiplayer is working fine in 18w09a smelting a cactus to produce cactus green doesn't work yet.
@unknown please don't report issues in the comment section, search for your bug or a create a new ticket.
From which version is it then? The crash report says 18w07b.