i am making my own custom launcher, your mod works perfectly under the regular minecraft launcher. and i have tried literally everything. from reading your code to matching every library 1 by 1 to make sure my custom launcher was launching minecraft the exact same way.

i even went as far as to read the GuideManager.java and make sure for each of your import statements that there was a matching loaded library. as far as i could tell there was.

this is the error i get when its launched using my launcher

net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from BuildCraft Lib (buildcraftlib)
Caused by: java.lang.NullPointerException
at buildcraft.lib.client.guide.GuideManager.reloadLang(GuideManager.java:50)
at buildcraft.lib.client.guide.GuideManager.load(GuideManager.java:44)
at buildcraft.lib.BCLibProxy$ClientProxy.fmlPostInit(BCLibProxy.java:134)
at buildcraft.lib.BCLib.postInit(BCLib.java:90)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:641)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:246)
at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:224)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
at com.google.common.eventbus.EventBus.post(EventBus.java:275)
at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:147)
at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:833)
at net.minecraftforge.fml.client.FMLClientHandler.finishMinecraftLoading(FMLClientHandler.java:356)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:521)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:352)
at net.minecraft.client.main.Main.main(SourceFile:124)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

i read your code, on line 50 it looks like its calling some language from the Minecraft client. the main jar file for minecraft is inside of my set of libraries. meaning the method its calling should be available. why is it saying that the command is nothing (What i believe nullpointer to be) is there something im missing. cause i cannot find it for the life of me.

my launcher is coded in vb.net. and is a private launcher/modpack buildcraft is the only mod its having issues launching with. please enlighten me on what may be missing. ive matched all the libraries that the normal launcher launches.

this would be super easy for you to tell me whats wrong i would imagine.

from the crash it looks your launcher is not exactly launching like the regular one

i'm not sure if we want to offer support here for custom launchers as iirc mojang does not allow those, you could make a wrapper launcher that starts the regular minecraft launcher, gives it the right params and the user only has to click play (or log in)

We're not going to provide support for custom launchers. We may be able to help if complete source code is provided to us, but it is unlikely that this issue will get priority. If you want a customized private modpack launcher, just take SKLauncher or MCUpdater and adapt it to your needs - or, if you don't need live delta updates, use MultiMC.

super easy for you to tell me whats wrong

Minecraft's launching process is a complex set of moving parts, really. It's not easy.

@AlexIIL I would like to point out that asking for the current language in postInit might not end well... it can change.

I hope you do change that soon. I just went ahead and reverted to 1.10.2 (because buildcraft is ahead of alot of the add-ons for IC2 and Opencomputers) . And my launcher does work with every other mod we added. Perhaps it's just that your asking for it on post initialization. I have copied the command line exactly from the regular launcher. So I'm not sure what else I can match. I thought maybe there was a specific library that you could tell me to include. Since you do the same thing in eclipse.

@asiekierka yes, its not ideal atm - although I will add reloading later on when resources change or the language used changes.

@Trickster29 I don't know how I can really help with this - the only thing I can assume is that you don't setup the resources properly and so it doesn't load any languages. Although I can add a check in case it is null, and default to en_us.

@AlexIIL My launcher has the normal languages button at the main menu. And all languages are available for picking. But if I pick a language. It does in fact not change anything. Do you have an idea on where the language resources are stored. So that I may figure out how to add then?

Maybe that's why the other mods load. Cause they assume english when there's nothing???

I stand corrected. It does in fact change stuff with the languages....