We have created a server with the modpack attack of the B team and only since yesterday it crashes after its start, i think this is due to our oxygen sealer ( fill a certain area with oxygen and check every second if the area is still sealed because it doesn't work in a too large area ) but we were already using these "oxygen sealer" and the server never crashed.
we have recently made a huge pit with TNT ( ~ 2*64 TNT ) maybe it can be another reason
when i connect i first see my moon base where i was the last time ( it is in a sealed area )
then i fall in a block and then i don't see any blocks only stars and then the server crashes : at least to the player because on the website it is shown as always active even after minutes ( and it thinks that i'm still connected ).
here is the console log :
2018-12-06 19:06:08 [INFO] Starting minecraft server version 1.6.4
2018-12-06 19:06:46 [INFO] Loading properties
2018-12-06 19:06:46 [INFO] Default game type: SURVIVAL
2018-12-06 19:06:46 [INFO] Generating keypair
2018-12-06 19:06:47 [INFO] Starting Minecraft server on *:10414
2018-12-06 19:06:52 [INFO] [qCraft] Loading qCraft v1.1 (rev 253)
2018-12-06 19:06:59 [INFO] Preparing level "world"
2018-12-06 19:07:00 [INFO] Preparing start region for level 0
2018-12-06 19:07:01 [INFO] Preparing spawn area: 14%
2018-12-06 19:07:01 [WARNING] Skipping TileEntity with id
2018-12-06 19:07:02 [INFO] Preparing spawn area: 44%
2018-12-06 19:07:03 [INFO] Done (3.828s)! For help, type "help" or "?"
2018-12-06 19:07:03 [INFO] Starting GS4 status listener
2018-12-06 19:07:03 [INFO] Query running on 0.0.0.0:10414
2018-12-06 19:07:38 [SEVERE] Reached end of stream for /176.139.10.22
2018-12-06 19:07:48 [INFO] Kamoul0x[/176.139.10.22:50134] logged in with entity id 157 at (69.68558227092129, 57.0, 361.518952608444)
2018-12-06 19:07:48 [INFO] Kamoul0x joined the game
2018-12-06 19:07:50 [SEVERE] Encountered an unexpected exception ReportedException
net.minecraft.util.ReportedException: Ticking tile entity
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:674)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:276)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:587)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)
Caused by: java.lang.NullPointerException
at micdoodle8.mods.galacticraft.core.oxygen.ThreadFindSeal.canBlockPassAirCheck(ThreadFindSeal.java:786)
at micdoodle8.mods.galacticraft.core.oxygen.ThreadFindSeal.<init>(ThreadFindSeal.java:93)
at micdoodle8.mods.galacticraft.core.oxygen.ThreadFindSeal.<init>(ThreadFindSeal.java:65)
at micdoodle8.mods.galacticraft.core.oxygen.OxygenPressureProtocol.updateSealerStatus(OxygenPressureProtocol.java:74)
at micdoodle8.mods.galacticraft.core.tile.GCCoreTileEntityOxygenSealer.func_70316_g(GCCoreTileEntityOxygenSealer.java:123)
at net.minecraft.world.World.func_72939_s(World.java:2209)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:550)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:668)
... 4 more
2018-12-06 19:07:50 [SEVERE] This crash report has been saved to: /aternos/server/./crash-reports/crash-2018-12-06_19.07.50-server.txt
2018-12-06 19:08:20 [SEVERE] Reached end of stream for /176.139.10.22
2018-12-06 19:08:27 [SEVERE] Reached end of stream for /176.139.10.22
2018-12-06 19:08:38 [SEVERE] Reached end of stream for /176.139.10.22
2018-12-06 19:09:54 [SEVERE] Reached end of stream for /176.139.10.22
2018-12-06 19:12:07 [INFO] Saving...
2018-12-06 19:12:07 [INFO] Saved the world
2018-12-06 19:17:07 [INFO] Successfully set the idle timeout to 10 minutes.
2018-12-06 19:17:07 [INFO] Saving...
2018-12-06 19:17:07 [INFO] Saved the world
2018-12-06 19:22:07 [INFO] Saving...
2018-12-06 19:22:07 [INFO] Saved the worldwhen i try to reconnect it takes a little time saying logging in and then: read timed out
i'd like to upload screenshots but i can't find how 
thanks to help me 
!