i updated BuildCraft Mod and buildcraft-compat to 7.2.4 and 7.2.1,and i found some problem:

if i place some pipe they will invisible! they not disappear,but it is just can't visible.and i can't destroy this pipe.

my server console can't not stop to display the ERROR like this :

A TileEntity type buildcraft.transport.TileGenericPipe has throw an exception trying to write state. It will not persist. Report this to the mod author java.lang.NullPointerException

what happen ? :(

this is my server log.
log.zip

Full ERROR:

[Server thread/ERROR] [FML]: A TileEntity type buildcraft.transport.TileGenericPipe has throw an exception trying to write state. It will not persist. Report this to the mod author java.lang.NullPointerException at buildcraft.transport.TileGenericPipe.func_145841_b(TileGenericPipe.java:266) ~[TileGenericPipe.class:?] at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75820_a(AnvilChunkLoader.java:368) [anj.class:?] at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75816_a(AnvilChunkLoader.java:165) [anj.class:?] at net.minecraft.world.gen.ChunkProviderServer.func_73242_b(ChunkProviderServer.java:238) [ld.class:?] at net.minecraft.world.gen.ChunkProviderServer.func_73151_a(ChunkProviderServer.java:298) [ld.class:?] at net.minecraft.world.WorldServer.func_73044_a(WorldServer.java:905) [le.class:?] at net.minecraft.server.MinecraftServer.func_71267_a(MinecraftServer.java:366) [MinecraftServer.class:?] at net.minecraft.server.MinecraftServer.func_71260_j(MinecraftServer.java:398) [MinecraftServer.class:?] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:534) [MinecraftServer.class:?] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_74]

Oh woops, thanks for reporting this!

I'm just building a Jar file that should stop the crashing, however there was an issue with saving the pipes anyway (they were invalid) so there was still a problem with pipes.

Can you try using this file and see what errors it gives? Also what types of pipes are you trying to use?

Also what mods are you using?

oh. this is my mod list:

at client:

at server:

about my pipes types,actually I'm not sure what causes this problem.
i remember after updated i want to move my pipes to other place, when i place the pipe (golden pipe),and i saw the pipe invisible,i tried to remove this pipe but i can't .

i can jump up to this pipe ,and this pipe can block me.

BTW: i Returned to 7.2.3,now i can place the pipe again,but some pipe (place in 7.2.4) still can't not visible and indestructible.

now i will use your new version to test ,wait a min

oh nice ! the problem has been fix!

i can place the pipe by normally!

but... what happen when i join the server..?
this is BUG too or some wrong texture?
when i reconnected , it will back to normal.

Its defiantly a bug as that's not right :)

Did it fix itself or did using my version fix it for you? If you disconnect+reconnect do the pipes go back to normal?

yep , this version is fix my problem ,the broken pipe is gone , thanks!!

if i found some new BUG or idea i will tell you :D

ok, thanks :)