Server appears to load then [SEVERE] issues happen

[Killuas]

Last night I left my server fine, and this morning a long list of issues that were labeled [sEVERE] happened while I was asleep. I tried restarting my server and still get the issues. I'm not sure what they mean or what is wrong. Can someone please help me with solving this? Thanks in advance.

11:51:36 [sEVERE] java.lang.ArrayIndexOutOfBoundsException: -1

11:51:36 [sEVERE] at buildcraft.transport.PipeTransportLiquids$LiquidBuffe

r.update(PipeTransportLiquids.java:395)

11:51:36 [sEVERE] at buildcraft.transport.PipeTransportLiquids.moveLiquids

(PipeTransportLiquids.java:145)

11:51:36 [sEVERE] at buildcraft.transport.PipeTransportLiquids.updateEntit

y(PipeTransportLiquids.java:55)

11:51:36 [sEVERE] at buildcraft.transport.Pipe.updateEntity(Pipe.java:106)

11:51:36 [sEVERE] at buildcraft.transport.TileGenericPipe.q_(TileGenericPi

pe.java:152)

11:51:36 [sEVERE] at net.minecraft.server.World.tickEntities(World.java:11

91)

11:51:36 [sEVERE] at net.minecraft.server.MinecraftServer.w(MinecraftServe

r.java:547)

11:51:36 [sEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftSer

ver.java:453)

11:51:36 [sEVERE] at net.minecraft.server.ThreadServerApplication.run(Sour

ceFile:492)

11:51:36 [sEVERE] Unexpected exception

java.lang.ArrayIndexOutOfBoundsException: -1

at buildcraft.transport.PipeTransportLiquids$LiquidBuffer.update(PipeTra

nsportLiquids.java:395)

at buildcraft.transport.PipeTransportLiquids.moveLiquids(PipeTransportLi

quids.java:145)

at buildcraft.transport.PipeTransportLiquids.updateEntity(PipeTransportL

iquids.java:55)

at buildcraft.transport.Pipe.updateEntity(Pipe.java:106)

at buildcraft.transport.TileGenericPipe.q_(TileGenericPipe.java:152)

at net.minecraft.server.World.tickEntities(World.java:1191)

at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:547)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:453)

at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)

[DeathxxAngelxx]

Have you op'ed Buildcraft?

[Killuas]

What do you mean by op'ed Buildcraft?

[DeathxxAngelxx]

if your running PEX it someones fucks up do

/op [buildcraft]

[Killuas]

It didn't fix the errors doing that.