My husband runs a private Minecraft server for our family.  Everything is updated on it, runs vanilla.

I have too have full vanilla, not even a resource pack running, on a Windows 7 machine, Java version 1.8.0_191 and it says everything is updated. I don't notice problems on singleplayer but in our server in the last two snapshots, even with brand new maps, I get 100 or so blocks and then the world appears to end.  I can see a few blocks here and there but can not cross. If I go into it I fall about 30 or so blocks and either smother or drown to death.  Occasionally I can get around it to other areas but sometimes I just have to quit. Sometimes I can come back in and it's fixed for several more blocks and other times not. 

Tonight during one of these glitches it crashed completely and gave me this message:
The game crashed whilst tesselating block model
Error: java.lang.NullPointerException: Tesselating block model

And this in the Log:

---- Minecraft Crash Report ----
// On the bright side, I bought you a teddy bear!

Time: 11/7/18 6:00 PM
Description: Tesselating block model

java.lang.NullPointerException: Tesselating block model
at czt$$Lambda$1387/1928313429.getColor(Unknown Source)
at czt.a(SourceFile:27)
at czt.a(SourceFile:38)
at cmf.k(SourceFile:41)
at cmf$$Lambda$1184/383876715.getColor(Unknown Source)
at cmf.a(SourceFile:103)
at dax.a(SourceFile:235)
at dax.c(SourceFile:106)
at dax.a(SourceFile:47)
at dav.a(SourceFile:60)
at dcu.b(SourceFile:220)
at dcr.a(SourceFile:88)
at dcr.run(SourceFile:41)
at java.lang.Thread.run(Thread.java:745)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Thread: Client thread
Stacktrace:
at czt$$Lambda$1387/1928313429.getColor(Unknown Source)
at czt.a(SourceFile:27)
at czt.a(SourceFile:38)
at cmf.k(SourceFile:41)
at cmf$$Lambda$1184/383876715.getColor(Unknown Source)
at cmf.a(SourceFile:103)
at dax.a(SourceFile:235)
at dax.c(SourceFile:106)

– Block model being tesselated –
Details:
Block: Block{minecraft:grass_block}[snowy=false]
Block location: World: (-81,64,1615), Chunk: (at 15,4,15 in -6,100; contains blocks -96,0,1600 to -81,255,1615), Region: (-1,3; contains chunks -32,96 to -1,127, blocks -512,0,1536 to -1,255,2047)
Using AO: false
Stacktrace:
at dax.a(SourceFile:47)

– Block being tesselated –
Details:
Block: Block{minecraft:grass_block}[snowy=false]
Block location: World: (-81,64,1615), Chunk: (at 15,4,15 in -6,100; contains blocks -96,0,1600 to -81,255,1615), Region: (-1,3; contains chunks -32,96 to -1,127, blocks -512,0,1536 to -1,255,2047)
Stacktrace:
at dav.a(SourceFile:60)

– Affected level –
Details:
Level name: MpServer
All players: 2 total; [czm['KeishaJL'/14436, l='MpServer', x=-23.06, y=62.07, z=1491.60], czn['johncub'/281, l='MpServer', x=141.08, y=64.00, z=1477.59]]
Chunk stats: MultiplayerChunkCache: 441, 5374
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options: {}
Level spawn location: World: (96,64,122), Chunk: (at 0,4,10 in 6,7; contains blocks 96,0,112 to 111,255,127), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 49765 game time, 83525 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: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 86 total; [akv['Bat'/28161, l='MpServer', x=-11.50, y=21.00, z=1525.50], apl['Zombie'/28169, l='MpServer', x=9.50, y=28.00, z=1549.50], czm['KeishaJL'/14436, l='MpServer', x=-23.06, y=62.07, z=1491.60], apc['Skeleton'/28684, l='MpServer', x=-38.50, y=24.00, z=1527.50], apc['Skeleton'/28685, l='MpServer', x=-33.50, y=24.00, z=1526.50], apc['Skeleton'/28686, l='MpServer', x=-32.50, y=24.00, z=1526.50], apc['Skeleton'/28687, l='MpServer', x=-32.50, y=24.00, z=1528.50], alp['Rabbit'/17, l='MpServer', x=30.19, y=66.00, z=80.60], alv['Tropical Fish'/26385, l='MpServer', x=94.34, y=62.00, z=1336.07], aof['Creeper'/28177, l='MpServer', x=-10.50, y=25.00, z=1525.50], czn['johncub'/281, l='MpServer', x=162.67, y=64.00, z=1476.20], apc['Skeleton'/28438, l='MpServer', x=-38.50, y=29.00, z=1449.50], apc['Skeleton'/28694, l='MpServer', x=-44.50, y=12.00, z=1527.50], apc['Skeleton'/28439, l='MpServer', x=-37.50, y=29.00, z=1451.50], czn['johncub'/281, l='MpServer', x=141.08, y=64.00, z=1477.59], apl['Zombie'/28697, l='MpServer', x=-91.35, y=25.00, z=1546.50], apc['Skeleton'/28444, l='MpServer', x=40.50, y=51.00, z=1562.50], apc['Skeleton'/28445, l='MpServer', x=41.50, y=51.00, z=1562.50], apc['Skeleton'/28206, l='MpServer', x=-40.50, y=21.00, z=1510.50], apc['Skeleton'/28207, l='MpServer', x=-44.50, y=21.00, z=1510.50], alv['Tropical Fish'/25664, l='MpServer', x=8.50, y=56.00, z=1261.50], ara['Minecart with Chest'/25920, l='MpServer', x=56.50, y=9.06, z=1523.50], aof['Creeper'/28737, l='MpServer', x=-38.50, y=16.00, z=1508.50], apc['Skeleton'/28488, l='MpServer', x=-15.50, y=20.00, z=1476.50], aof['Creeper'/28489, l='MpServer', x=26.50, y=37.00, z=1542.50], apc['Skeleton'/28496, l='MpServer', x=-13.50, y=28.00, z=1520.50], alv['Tropical Fish'/27985, l='MpServer', x=28.12, y=59.87, z=1426.76], alv['Tropical Fish'/27986, l='MpServer', x=27.75, y=59.39, z=1426.52], alv['Tropical Fish'/27988, l='MpServer', x=32.26, y=59.91, z=1431.13], alv['Tropical Fish'/27989, l='MpServer', x=29.84, y=60.03, z=1430.61], alv['Tropical Fish'/27990, l='MpServer', x=30.98, y=59.98, z=1433.01], alv['Tropical Fish'/27993, l='MpServer', x=24.22, y=59.93, z=1430.52], apl['Zombie'/28249, l='MpServer', x=-64.48, y=21.00, z=1467.75], aof['Creeper'/28251, l='MpServer', x=-43.41, y=15.00, z=1489.79], alu['Squid'/27996, l='MpServer', x=12.95, y=62.81, z=1431.49], apc['Skeleton'/28510, l='MpServer', x=6.50, y=26.00, z=1507.50], czn['johncub'/281, l='MpServer', x=91.03, y=63.15, z=1161.32], aof['Creeper'/28777, l='MpServer', x=-59.50, y=45.00, z=1499.50], alv['Tropical Fish'/28013, l='MpServer', x=45.66, y=61.61, z=1433.30], alv['Tropical Fish'/28017, l='MpServer', x=45.77, y=61.95, z=1437.41], alo['Pufferfish'/28020, l='MpServer', x=32.52, y=55.92, z=1429.48], alv['Tropical Fish'/28022, l='MpServer', x=25.44, y=57.44, z=1426.96], aqy['Boat'/27511, l='MpServer', x=-23.06, y=62.52, z=1491.60], alv['Tropical Fish'/28023, l='MpServer', x=26.35, y=57.10, z=1428.34], apl['Zombie'/28279, l='MpServer', x=50.50, y=5.00, z=1525.50], alv['Tropical Fish'/28024, l='MpServer', x=26.13, y=56.98, z=1427.27], alv['Tropical Fish'/28025, l='MpServer', x=26.95, y=57.00, z=1427.50], apc['Skeleton'/28281, l='MpServer', x=20.50, y=40.00, z=1574.50], alv['Tropical Fish'/28026, l='MpServer', x=26.91, y=56.99, z=1428.06], aof['Creeper'/28283, l='MpServer', x=-29.50, y=25.00, z=1521.50], alv['Tropical Fish'/28028, l='MpServer', x=26.15, y=57.07, z=1426.74], aof['Creeper'/28284, l='MpServer', x=-31.50, y=25.00, z=1521.50], apl['Zombie'/28546, l='MpServer', x=-78.50, y=29.00, z=1554.50], apl['Zombie'/28547, l='MpServer', x=-77.50, y=29.00, z=1552.50], apl['Zombie'/28548, l='MpServer', x=-77.50, y=29.00, z=1554.50], any['Red Mushroom'/21638, l='MpServer', x=249.88, y=15.00, z=1242.88], alo['Pufferfish'/28584, l='MpServer', x=41.50, y=60.00, z=1450.50], apl['Zombie'/28073, l='MpServer', x=56.50, y=36.00, z=1480.50], alv['Tropical Fish'/28585, l='MpServer', x=47.50, y=60.00, z=1447.50], apc['Skeleton'/28587, l='MpServer', x=-38.50, y=15.00, z=1501.50], czm['KeishaJL'/14436, l='MpServer', x=190.67, y=54.57, z=1254.81], apf['Spider'/28602, l='MpServer', x=-31.50, y=17.00, z=1491.50], aof['Creeper'/28348, l='MpServer', x=-26.50, y=21.00, z=1508.50], akv['Bat'/28097, l='MpServer', x=35.32, y=47.03, z=1542.45], aof['Creeper'/28353, l='MpServer', x=-39.50, y=14.00, z=1493.50], akv['Bat'/28098, l='MpServer', x=-20.45, y=19.04, z=1486.93], apc['Skeleton'/28356, l='MpServer', x=-18.50, y=19.00, z=1517.50], apc['Skeleton'/28880, l='MpServer', x=10.50, y=33.00, z=1543.50], apl['Zombie'/28113, l='MpServer', x=20.50, y=37.00, z=1546.50], apc['Skeleton'/28881, l='MpServer', x=-3.50, y=22.00, z=1516.50], aof['Creeper'/28370, l='MpServer', x=-27.50, y=18.00, z=1489.50], aof['Creeper'/28882, l='MpServer', x=-6.50, y=22.00, z=1515.50], aof['Creeper'/28371, l='MpServer', x=-30.50, y=18.00, z=1488.50], aof['Creeper'/28883, l='MpServer', x=-11.50, y=22.00, z=1513.50], aof['Creeper'/28884, l='MpServer', x=-3.50, y=22.00, z=1517.50], akv['Bat'/28885, l='MpServer', x=21.50, y=43.00, z=1558.50], akv['Bat'/28890, l='MpServer', x=-23.50, y=18.00, z=1545.50], apc['Skeleton'/28646, l='MpServer', x=-59.50, y=18.00, z=1477.50], apc['Skeleton'/28647, l='MpServer', x=-58.50, y=18.00, z=1478.50], apl['Zombie'/28908, l='MpServer', x=-90.50, y=25.00, z=1548.50], apc['Skeleton'/28148, l='MpServer', x=-27.50, y=18.00, z=1490.50], apc['Skeleton'/28149, l='MpServer', x=-32.29, y=19.00, z=1487.51], apl['Zombie'/28150, l='MpServer', x=-30.50, y=18.00, z=1494.50], apl['Zombie'/28151, l='MpServer', x=-26.50, y=18.00, z=1490.50], apc['Skeleton'/28668, l='MpServer', x=-7.50, y=22.00, z=1485.50], czn['johncub'/281, l='MpServer', x=141.08, y=64.00, z=1477.59]]
Retry entities: ~_ERROR~ ConcurrentModificationException: null
Server brand: vanilla
Server type: Non-integrated multiplayer server
Stacktrace:
at cxj.a(SourceFile:368)
at clx.b(SourceFile:1864)
at dcr.run(SourceFile:47)
at java.lang.Thread.run(Thread.java:745)

– System Details –
Details:
Minecraft Version: 18w45a
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 164860000 bytes (157 MB) / 615641088 bytes (587 MB) up to 3207856128 bytes (3059 MB)
JVM Flags: 7 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xss1M -Xmx3G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
Launched Version: 18w45a
LWJGL: 3.1.6 build 14
OpenGL: NO CONTEXT
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: Yes
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: vanilla
Current Language: English (US)
CPU: 4x AMD FX(tm)-4100 Quad-Core Processor