Recommendation: In settings, set your custom arguments to include -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M.

Heads-up: I experienced repeated crashes with ftb-app-bin that triggered massive coredumps (each consuming 20–25 GB of memory and significant CPU time via systemd-coredump).

The journal showed errors like:

Code FATAL:platform_shared_memory_region_posix.cc(219) This is frequently caused by incorrect permissions on /dev/shm. However, /dev/shm had correct permissions (drwxrwxrwt) and was mounted as tmpfs, though it included the usrquota flag. I didn’t fully debug this, but it’s possible the bundled Electron runtime or a missing rebuild after a so.bump is involved.

Switched to the Flatpak version and the issue disappeared entirely — no crashes, no coredumps.

Just leaving this here in case others hit the same issue. Not looking to troubleshoot further — Flatpak works fine for now.

@Saiyaman Sorry for late reply, it should be fixed now. But there's no need to use AppImage, just delete /opt/ftb-app/resources/package-type and everything will be fine.

I notice with this one it tries to immediately update on launch but it grabs a deb file and tries to run a command using apt. This doesn't work and causes a really annoying but endless cycle of the app closing and restarting.

23:52:02.676 › Executing: /usr/bin/pkexec --disable-internal-agent with args: /bin/bash,-c,'dpkg -i /home/<user>/.cache/ftb-app-updater/pending/ftb-app-1.25.10-amd64.deb || apt-get install -f -y' 23:52:40.705 › [23:52:40][D][ftb-app::background.ts] Download promise resolved obj([ '/home/<user>/.cache/ftb-app-updater/pending/ftb-app-1.25.10-amd64.deb' ]) 23:52:40.706 › Update installer has already been triggered. Quitting application.

Is it possible to support an app image on aur? I guess I could go grab that and I'm sure it would work over this but here was that output.

23:52:02.451 › Found version 1.25.10 (url: ftb-app-1.25.10-x86_64.AppImage, ftb-app-1.25.10-amd64.deb, ftb-app-1.25.10-amd64.deb, ftb-app-1.25.10-amd64.deb, ftb-app-1.25.10-x86_64.rpm, ftb-app-1.25.10-x86_64.rpm, ftb-app-1.25.10-x86_64.rpm) 3:52:02.451 › [23:52:02][D][ftb-app::background.ts] Emitting downloader event updater:update-available obj([]) 23:52:02.452 › Downloading update from ftb-app-1.25.10-x86_64.AppImage, ftb-app-1.25.10-amd64.deb, ftb-app-1.25.10-amd64.deb, ftb-app-1.25.10-amd64.deb, ftb-app-1.25.10-x86_64.rpm, ftb-app-1.25.10-x86_64.rpm, ftb-app-1.25.10-x86_64.rpm 23:52:02.452 › updater cache dir: /home/<user>/.cache/ftb-app-updater 23:52:02.453 › [23:52:02][D][ftb-app::background.ts] Waiting for download promise 23:52:02.661 › Update has already been downloaded to /home/<user>/.cache/ftb-app-updater/pending/ftb-app-1.25.10-amd64.deb).

Diff for latest version

diff --git a/PKGBUILD b/PKGBUILD
index 5ce98f5..bb9e9a7 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -3,7 +3,7 @@
 # Contributor: William Brown <glowinthedarkcia at horsefucker dot org>

 pkgname=ftb-app-bin
-pkgver=1.25.8
+pkgver=1.25.9
 pkgrel=1
 epoch=
 pkgdesc="A new Modpack launcher for FTB and Curse modpacks."
@@ -26,8 +26,8 @@ changelog=
 source_x86_64=("https://piston.feed-the-beast.com/app/ftb-app-${pkgver}-amd64.deb")
 source_aarch64=("https://piston.feed-the-beast.com/app/ftb-app-${pkgver}-arm64.deb")
 noextract=()
-sha256sums_x86_64=(5c304798857e3bc584a8762d85be84fbac812c157fac863de1c9bf20566fb013)
-sha256sums_aarch64=(072d7d46c0cf7580f344dd03838744a74d097cbcaafaac0d9b5f642de62c3f4b)
+sha256sums_x86_64=(ed383f018f64dbfb7c393331bd83b13ec9b6ad14d277eeb609eb8b22b6a45348)
+sha256sums_aarch64=(d108362cb0b6caecb84366353b8903c6d077cebb03e91e4ea75c668a36887c4b)
 validpgpkeys=()

 package() {

I assume this fails to run with electron23?

I just got yesterdays build and it doesn't load any web elements. My library for the mod pack I use loads but the other pages that rely on a web server to load do not. So I cannot see modpacks list. I've not seen a github bug about this.

EDIT: Delete .ftba from home directory. Backup your worlds!

I should probably be listed in the PKGBUILD as contributor, not maintainer.

If you push and update just to fix this, you don't need to change pkgrel.

I have stopped using this and now use ATLauncher (which works the best for me), so I am disowning this package.

Recommendation: In settings, set your custom arguments to include -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M.

If you're trying to run the game and it fails, and this shows up in your logs

locale::facet::_S_create_c_locale name not valid

You need to enable US English on your system. Uncomment the en_US.UTF-8 UTF-8 line in your /etc/locale.gen file then run sudo locale-gen