[Bug] Can't download forge modpacks

[x1msoc]

What Operating System

Linux (Other)

Debug Code

FTB-DBGAMITEGASIH

Describe the bug

I'm unable to download any Forge modpacks. I can download any Fabric/NeoForge modpack.

Steps to reproduce

1. Find any modpack with Forge Mod Loader.
2. Click the download button.
3. After a while, the app crashes with the exception I mentioned below.

Expected behaviour

Successful download and install of any forge modpack

Screenshots

Additional information

[ftb-app::background.ts] Subprocess stdout [16:57:04] [Long Running Executor 0/ERROR] [net.creeperhost.creeperlauncher.task.InstallationOperation]: Fatal exception whilst installing modpack.
net.creeperhost.creeperlauncher.install.InstanceInstaller$InstallationFailureException: Failed to install.
        at net.creeperhost.creeperlauncher.install.InstanceInstaller.execute(InstanceInstaller.java:317) ~[launcher-b53a6f5ed2-all.jar:?]
        at net.creeperhost.creeperlauncher.task.InstallationOperation.doOperation(InstallationOperation.java:49) ~[launcher-b53a6f5ed2-all.jar:?]
        at net.creeperhost.creeperlauncher.task.LongRunningOperation.lambda$wrapOperation$0(LongRunningOperation.java:74) ~[launcher-b53a6f5ed2-all.jar:?]
        at net.covers1624.quack.util.SneakyUtils.lambda$concat$9(SneakyUtils.java:111) ~[launcher-b53a6f5ed2-all.jar:?]
        at java.util.concurrent.CompletableFuture$AsyncRun.run(Unknown Source) ~[?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[?:?]
        at java.lang.Thread.run(Unknown Source) ~[?:?]
Caused by: java.io.IOException: Processor output validation errors occurred.
        at net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask.runProcessor(ForgeV2InstallTask.java:338) ~[launcher-b53a6f5ed2-all.jar:?]
        at net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask.runProcessors(ForgeV2InstallTask.java:187) ~[launcher-b53a6f5ed2-all.jar:?]
        at net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask.execute(ForgeV2InstallTask.java:98) ~[launcher-b53a6f5ed2-all.jar:?]
        at net.creeperhost.creeperlauncher.install.InstanceInstaller.execute(InstanceInstaller.java:260) ~[launcher-b53a6f5ed2-all.jar:?]
        ... 7 more

I get this exception every time the app fails to load the modpack

OS: Fedora 40 (kernel version: 6.9.4-200.fc40.x86_64), KDE Plasma: 6.1.0

[Gaz492]

Would you be able to go to ~/.ftba/bin/ then rename the libraries folder to libraries-old and try again, the app looks to be running into an issue validating 2 files from minecraft.

[x1msoc]

Same expection. I suspect that launcher is getting wrong SHA1 hash from server and fails to validate.

[x1msoc]

Update: I found that I could not download any Forge 1.18.2 modpacks (FTB/CF)

[Gaz492]

Does vanilla 1.18.2 work for you?

[x1msoc]

I can't create any modpack at all, only download from FTB or CF. Nothing in logs

[Anroch2020]

I can confirm that none of the modpacks that use forge <=1.19 can be installed with the linux app, this include curseforge and ftb modpacks, the problem is caused by the modloader installer
Relevant Log:
9:58:41.242 › [19:58:41][D][ftb-app::background.ts] Subprocess stdout [19:58:41] [Long Running Executor 0/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Output '/home/achinchilla/.ftba/bin/libraries/net/minecraft/client/1.18.2-20220404.173914/client-1.18.2-20220404.173914-slim.jar' failed to validate. [19:58:41] [Long Running Executor 0/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Expected: 2b8907919c1d51fda0b2ace0eba8a8b73855198f 19:58:41.243 › [19:58:41][D][ftb-app::background.ts] Subprocess stdout [19:58:41] [Long Running Executor 0/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Got : 647639f51b069331344d5e70ffe625dc87c1eccb 19:58:41.248 › [19:58:41][D][ftb-app::background.ts] Subprocess stdout [19:58:41] [Long Running Executor 0/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Output '/home/achinchilla/.ftba/bin/libraries/net/minecraft/client/1.18.2-20220404.173914/client-1.18.2-20220404.173914-extra.jar' failed to validate. [19:58:41] [Long Running Executor 0/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Expected: 52e1b15676c03b5e1b769f5bd7d89426e9807c89 [19:58:41] [Long Running Executor 0/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Got : ddfb5452a4d6ddfe4ac59153a19a2e006c8d0a44 [19:58:41] [Long Running Executor 0/ERROR] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Processor output validation errors occurred. 19:58:41.253 › [19:58:41][D][ftb-app::background.ts] Subprocess stdout [19:58:41] [Long Running Executor 0/ERROR] [net.creeperhost.creeperlauncher.task.InstallationOperation]: Fatal exception whilst installing modpack. net.creeperhost.creeperlauncher.install.InstanceInstaller$InstallationFailureException: Failed to install. at net.creeperhost.creeperlauncher.install.InstanceInstaller.execute(InstanceInstaller.java:317) ~[launcher-b53a6f5ed2-all.jar:?] at net.creeperhost.creeperlauncher.task.InstallationOperation.doOperation(InstallationOperation.java:49) ~[launcher-b53a6f5ed2-all.jar:?] at net.creeperhost.creeperlauncher.task.LongRunningOperation.lambda$wrapOperation$0(LongRunningOperation.java:74) ~[launcher-b53a6f5ed2-all.jar:?] at net.covers1624.quack.util.SneakyUtils.lambda$concat$9(SneakyUtils.java:111) ~[launcher-b53a6f5ed2-all.jar:?] at java.util.concurrent.CompletableFuture$AsyncRun.run(Unknown Source) ~[?:?] at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[?:?] at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[?:?] at java.lang.Thread.run(Unknown Source) ~[?:?] Caused by: java.io.IOException: Processor output validation errors occurred. at net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask.runProcessor(ForgeV2InstallTask.java:338) ~[launcher-b53a6f5ed2-all.jar:?] at net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask.runProcessors(ForgeV2InstallTask.java:187) ~[launcher-b53a6f5ed2-all.jar:?] at net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask.execute(ForgeV2InstallTask.java:98) ~[launcher-b53a6f5ed2-all.jar:?] at net.creeperhost.creeperlauncher.install.InstanceInstaller.execute(InstanceInstaller.java:260) ~[launcher-b53a6f5ed2-all.jar:?] ... 7 more 19:58:41.253 › [19:58:41][D][ftb-app::background.ts] Subprocess stdout [19:58:41] [Long Running Executor 0/INFO] [net.creeperhost.creeperlauncher.task.LongRunningTaskManager]: Completing LongRunningOp: net.creeperhost.creeperlauncher.task.InstallationOperation@5dfb4c9c

[Anroch2020]

FTB Neotech and other modpacks that use forge version>=1.20 are installed correctly and without any problem

[paradust7]

@Gaz492 The .jar files are failing validation because they have different compression than the ones with the right checksum. The uncompressed contents are identical byte-for-byte, but the jar file is slightly bigger.

10857 files, 13319467 bytes uncompressed, 7153550 bytes compressed:  46.3%
10857 files, 13319467 bytes uncompressed, 7195073 bytes compressed:  46.0%

These files are being generated by ftb app on the client, from the base file bin/versions/1.18.2/1.18.2.jar
The jar splitter which generates those files is part of Forge.

It uses java.util.zip, which probably uses the system zlib. And so it could be sensitive to changes in zlib version/config.

[william-dickinson]

I can also confirm this behavior running on Fedora 40. I am able to install and run FTB NeoTech but cannot do so with for instance Direwolf20. I've put the relevant lines from my debug.log below - and I am running zlib-ng-compat-2.1.7-1.fc40.x86_64 if that's useful.

[23:53:45.160] [Long Running Executor 2/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Output '/home/user/.ftba/bin/libraries/net/minecraft/client/1.20.1-20230612.114412/client-1.20.1-20230612.114412-extra.jar' failed to validate.
[23:53:45.160] [Long Running Executor 2/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]:  Expected: 8c5a95cbce940cfdb304376ae9fea47968d02587
[23:53:45.160] [Long Running Executor 2/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]:  Got     : cf941ba69e11f5a9de15d0c319d61854c456a116
[23:53:45.166] [Long Running Executor 2/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Output '/home/user/.ftba/bin/libraries/net/minecraft/client/1.20.1-20230612.114412/client-1.20.1-20230612.114412-slim.jar' failed to validate.
[23:53:45.166] [Long Running Executor 2/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]:  Expected: de86b035d2da0f78940796bb95c39a932ed84834
[23:53:45.166] [Long Running Executor 2/WARN] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]:  Got     : a8fb49bc364562847d6e7e6775e3a1b3f6b2bb05
[23:53:45.166] [Long Running Executor 2/ERROR] [net.creeperhost.creeperlauncher.install.tasks.modloader.forge.ForgeV2InstallTask]: Processor output validation errors occurred.

[william-dickinson]

After some more investigating looks like this could be the same issue as this PR in forge: MinecraftForge/JarSplitter#2

[Gaz492]

Just wanted to check, is everyone here running into an issue running fedora?

[Gaz492]

We have released an update to the app which allows you to disable file hash verification.
This can be done by going to Settings > Advanced and enabling the Ignore (Neo)Forge processor hashes checks option.

I will keep this issue open for the time being, in case any further issues arise

[OffsetMonkey538]

For me, the same issue happens on Nobara 40 (based on Fedora) when trying to get a 1.20.1 modpack server running while using GraalVM 21, but gets fixed by switching to Temurin 17