BuildCraft version: 7.99.21
Forge version: forge-14.23.5.2807
Link to crash report or log:
crash-2019-01-21_00.32.29-client.txt

Singleplayer or multiplayer: Launching Minecraft

Steps to reproduce:
launch buildcraft (core - transport- compat-builders-energy)
when load.. the client crash (Adjunt crash report)
the game request buildcraftlib...

Additional information:
when i add buildcraftlib the game said me, i have 2 duplicated mods
latest.log

when i launch without BuilcraftCore (let libs like core since forge says they are the same mod)
all the modules need buildcraft core -.-

latest.log

The first part (buildcraftlib crashing) is caused by #4324, and can be temporarily fixed by either downgrading to 7.99.20, or waiting for 7.99.22 to come out, or downloading the "buildcraft-all-7.99.21.jar" file by itself (which includes all modules).

The second part is caused by our odd jar embedding structure: "buildcraft-lib-7.99.21.jar" contains 1 mod: buildcraftlib, but "buildcraft-core-7.99.21.jar" contains 2 mods: buildcraftlib and buildcraftcore. (The "buildcraft-all.7.99.21.jar" file contains all 9 modules: lib, core, builders, energy, factory, robotics, silicon, transport, and compat).

in the buildcraftlib crashing i tryed to put 7.99.20 but get the same error
crash-2019-01-21_13.05.51-client.txt
i cannot use the buildcraft-all because when i installit cause me a constant drop frames
and and innecesary objest (silicon module)

Oh right ok, apparently that bug has been in for a while before it was fixed then. So there's really little else that I can recommend other than "wait for me".

However "cause me a constant drop frames" - what sort of frame drops? That sounds like another bug that I need to fix :p.

(It might be an issue with too many animated fluid sprites that are added by the energy module that you can turn off in config/Performance/enableAnimatedSprites). Although if that doesn't work you can find out by opening up and navigating around the debug pie to find what parts of it are more expensive in one part than other bits.