Solved Server crashed and now crashes on launch

[Bockit]

I run a mindcrack server on my Mac Mini, OSX Mountain Lion.

Modpack: Mindcrack 'recommended', whatever the current Recommended version is in the launcher, I think it's 8.1.0 or 8.1.1. Not the 8.0.x version.

I was doing something involving filters, tesseracts, routers, transport pipes and timers. Basically a barrell with empty cells pulls out a stack once every 5 seconds and gets pneumatic tubed into a tesseract, which then comes out another tesseract into a diamond pipe which puts it into the router if there's space and overflows into a 2nd tesseract which adds it back into the barrel again on the other side.

However, the game crashed, and now it crashes on launch. I've attached the two crash logs.

Is there a way I can fix this, or do I have to roll back to a backup? Can I load the world file in an external program and delete the offending block identified in the crash logs?

Any help is appreciated, and thankyou for your time. If more information is needed I'm happy to provide it.

 

[Bockit]

I duplicated my world folder just in case and decided to do some research and tinkering of my own.

Going through the crash logs it appeared to be one of my diamond pipes:

-- Tile entity being ticked --
Details:
    Name: net.minecraft.src.buildcraft.transport.GenericPipe // buildcraft.transport.TileGenericPipe
    Block type: ID #0
    Block data value: Unknown? (Got -1)
    Block location: World: (-1344,22,337), Chunk: (at 0,1,1 in -84,21; contains blocks -1344,0,336 to -1329,255,351), Region: (-3,0; contains chunks -96,0 to -65,31, blocks -1536,0,0 to -1025,255,511)
Stacktrace:
    at yc.h(World.java:2153)
    at in.h(WorldServer.java:516)

Firstly, I tried using MCEdit[1] to go into the world with the intention of flying to the area and removing all the diamond pipes in the area. That didn't work, it doesn't play nice with FTB worlds it seems, funny to see greatwoods with redstone ore for leaves and torches for trunks for example. Also despite flying to the correct spot, I couldn't find what I had built, and the world gen seemed different...

With that out, I looked up other ways to edit mc worlds outside of the game. NBTExplorer[2] came up as an option. The crash log told me it was region -3, 0, and which chunk it was. You'll have to translate the chunk coordinates to locally within the region, as each region starts from 0, 0. I found the correct chunk, looked through tileentities and used the find next function of NBTExplorer to find the TileGenericPipe at the coordinates mentioned in the crash log.

From there it was a case of deleting the pipe.

The server booted up and didn't crash. I logged in and investigated the area and the pipe was removed, but if you moved your cursor over the space it was, there was a black box as if there was a block there. Hitting it with a vajra (what I had on me, not that other tools might not have worked) seemed to make it disappear, without the visual effects of a block breaking. Once that had disappeared I could place blocks in the space again. I've since recreated the situation and it's running ok now.

My best guess as to how this happened: I may have screwed up the filter settings of the diamond pipe, I use a used-tool as a filter on the side it enters from to stop it going back into the tesseract (which is set to receive only) I'm guessing I had this on the wrong colour, allowing items to go back into the tesseract. But this is just a guess, I haven't tried to recreate it and I don't even know if that was the case.

I hope this writeup can help someone else sometime in the future!

[1]: http://www.minecraftforum.net/topic/13807-mcedit-minecraft-world-editor-now-open-source/
[2]: http://www.minecraftforum.net/topic/840677-nbtexplorer-nbt-editor-for-windows-and-mac/ I recommend the windows client over the mac client if you have the choice, more features available, notably 'find next'