Posted to EnderIO at first. They requested I cross-post here.
SleepyTrousers/EnderIO-1.5-1.12#3796

Issue Description:

OK, really weird one. A player on my server reported her newly-crafted farming station behaving strangely. During my investigation I was able to establish:

• The problem was not unique to her particular farming station. The problem also happened with a spawned one, and one I had been using at my base for a while.
• If placed at Y=62, we get a thread crash on the server. If placed one block higher or lower, no problem.
• In the capacitor, we see power being drawn. In the farm, the energy buffer remains empty.
• Sometimes saplings are used but not placed.
• I couldn't replicate this problem at my base, so I flew around trying different biomes. Appears to be unique to the BoP Marsh biome and not dependent on chunk borders. I was only able to find two Marshes (opposite sides of the map). Tried in several vanilla and BoP biomes and the problem only appeared in the two marshes.
• A Vat did not exhibit the problem.
• Only happens when the farm tries to use power, but can be from a conduit or capacitor. For example, if the farm had some stored energy (from a negative test in a non-Marsh biome), simply placing the farm would result in the thread crash. Placing a capacitor next to it, would cause a second thread crash.

What you expected to happen:

Normal farm operation.

Steps to reproduce:

• Find a BoP "Marsh"
• Place a power source
• Place a farming station
• Observe thread crash on server console

Affected Versions (Do not use "latest"):

EnderIO: 3.0.1.120_beta
EnderCore: 0.4.1.56-beta
Minecraft: 1.10.2
Forge: 2107
BiomesOPlenty-1.10.2-5.0.0.2089-universal

Your most recent log file where the issue was present:

http://pastebin.com/2zZgbstX

Full server log here http://southernarmada.org/logs/fml-server-latest.zip

So I just tried to replicate this in my pack and couldn't, are you able to replicate with just BoP and EnderIO/core (+forge)?

I'll give it a go in the next couple of days.

Cheers!

Have you tried in the marsh with the farming station planting onto vanilla dirt not BoP dirt/grass. Potentially not the biome or height. BoP dirt/grass being used as the soil for farming stations caused a crash previously and I don't think it was ever fixed (I may be wrong)

Yes we did try it with regular dirt, (or even no dirt on the same level as the farming station).

Henry at EnderIO linked this one #807 which is still outstanding. It's been marked as a minor bug which is fair, because it's a pretty specific set of circumstances needed to trigger it :-)

OK, after a few hours of testing, I've isolated it to... drumroll extrautilities2.
Removing xu2 from my pack stops the problem from happening.
Running a stripped down pack (EnderIO/core/BoP/JEI) works fine and adding xu2 introduces the problem.
Again, farm at Y=62 results in a crash. farm at Y=63 does not.

I hope that helps.

FWIW: I did my testing in SSP. Placing a farm next to a creative capacitor in SSP results in a CTD whereas it was only a thread crash on the server. I haven't tested on our server because I just know it'll break the world file. I hope this is enough to help you find the cause.

The original crash is in BlockBOPGrass.canSustainPlantType(), which is #807 and will only be present if there are other mods installed that add plant types (which neither BoP nor Ender IO do).

This should be re-opened. It seems to not have been fixed.

@ouTPhaze what version of Biomes O plenty are you using?