server crashing

this is what happens everytime anyone one this server goes to nether.

[22:34:42] [Server thread/ERROR]: Chunk file at -34,11 is in the wrong location; relocating. (Expected -34, 11, got -35, 10)
[22:35:13] [Server thread/ERROR]: Encountered an unexpected exception
s: Exception ticking world
at net.minecraft.server.MinecraftServer.u(SourceFile:507) ~[minecraft_server.jar:?]
at lj.u(SourceFile:265) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.t(SourceFile:441) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:358) [minecraft_server.jar:?]
at ky.run(SourceFile:617) [minecraft_server.jar:?]
Caused by: java.lang.NullPointerException
at mi.c(SourceFile:199) ~[minecraft_server.jar:?]
at mj.b(SourceFile:120) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.u(SourceFile:503) ~[minecraft_server.jar:?]
... 4 more
[22:35:13] [Server thread/ERROR]: This crash report has been saved to:

this server has 10GB of ram that gets consumed by this update, we have tred less ram but the server crashes more when we do so please can you release an update to fix this issue.