Closed Eucalyptus Saplings - Despawning (due to invisible Arcane Lamp lights)

[Sorbe]

Summary of the problem Eucalyptus Saplings - Despawning. (Bug or Player Error?)

Pack Version 2.5.4

What is the bug? If I place down Eucalyptus Saplings on either a large open plot of dirt or grass, they usually "vanish" instead of creating a tree.

Sometimes, they actually create the tree, but not very often. This is true even if you bone meal them (after 2 or more) bone meals, they will vanish. I've tried this with single saplings and groups of them.

The last thing I noticed was that the name of the sapling name changed from "Eucalyptus Saplings" to some internal sapling identifier name, then they vanish after that.

Am I missing something critical about biomes or water or soil or whatever that is peculiar to Eucalyptus saplings and trees??

(I have all of the other vanilla, Natura, Thaumcraft trees growing successfully 100% under identical conditions)

Mod & Version ?

Link to log file

Is it repeatable? 90% of the time the Eucalyptus Sapling will vanish.
I've tried this in number of biomes with and without automation.

Known Fix None.

 

[Sorbe]

I believe this problem arises when Thaumcraft's Arcane Lamps spawn hidden lights above the saplings. I found this happening again and temporarily filled in the area above the saplings with blocks(sand) which I then removed. The trees started growing again.
Basically, some saplings will despawn if anything is above them (hidden or not) -- removing the non-air blocks lets them grown.

 

[Sorbe]

I've confirmed that if you "fill" the area above the saplings, and then remove the solid blocks and thus eliminate any hidden Arcane Lamp "inviso lights", the few sapling tree types that did not grow (Eucalypus and Greatwood) can be successfully grown again. This problem also affects the classic berry bushes as well (Blueberry, Raspberry, Blackberry, Maloberry).

There are two workarounds, avoid the Arcane Lamps altogether for these type of plants, or (this sometimes works) put normal torches around the saplings so the Arcane Lamp will not have a reason to place inviso light above them. This only partially works, since the resulting tree itself may present new unlit opportunities for the inviso lights to be placed.

IMO, this is not a modpack bug -- I would fault the affected saplings/plants for caring about these types of blocks when sprouting/growing since most of the saplings work just fine.