Crash Assistant in FTB Skies 2: Aero

Same as in the All the Mods 10 8.1 guide

Crash Assistant is a crash-helper mod. When Minecraft crashes, it pops up a window that immediately shows the affected game and launcher logs, crash reports and hs_err files. From there you can upload everything with one click and copy a link to paste into Discord or GitHub. The pack ships version 1.11.12.^[1][2]

It is client-only, so on a server it does nothing.^[1]

Who it is for

It is for anyone who crashes and wants to know why, and for people who help with support. You get a formatted, ready-to-paste report, and anyone helping you gets current logs without having to ask for more files. The mod's author says more than 75% of issues are common and easily solvable, and the analysis aims to cut that support load.^[1]

What it does for you

• Analyzes logs for many known crash causes. When it finds one, it shows a dialog with a description and a detailed fix. Examples include out-of-memory errors, duplicated mods, Mixin conflicts, and GPU driver problems.^[1]
• Warns you if Minecraft is running on an integrated GPU when a dedicated one is available, and offers a one-click Auto-Fix button on Windows.^[1]
• Warns you if your CPU is one of the Intel 13th/14th generation models known to have a critical stability bug.^[1]
• Includes analysis tools in the GUI menu, such as a Package/Class Finder that shows which mod contains a given Java class or package.^[1]
• Saves the modlist, and for modpack players it lists the mods you added, removed or updated compared with the official list. You can also save it manually with the /crash_assistant modlist save command.^[1]

It runs as a separate process that waits for the Minecraft JVM to stop. It also loads very early, so it can catch crashes during startup.^[1]

Where it fits in the pack

Crash Assistant is a utility rather than a gameplay mod, so it adds no progression of its own. You don't need to unlock or craft anything. It is there when something goes wrong.^[1]

Unverified The sources I was given show no quests or ATM Star path involvement for this mod, and no in-jar guidebook was found for it.

Crash Assistant is a safety net, not something you build. After Minecraft crashes it shows a window with all the affected game and launcher logs, crash reports or hs_err files. From there you can upload them, copy the link and analyse the cause. The mod is client-only, so on a server it does nothing.^[1]

What to know before your first crash

1. Nothing needs switching on. In this pack the main features are already enabled: log analysis (analysis.enabled), the analysis tools (analysis_tools.enabled) and the compatibility feature (compatibility.enabled).^[3]
2. When a crash happens, the window lists the logs it found. It can also show up when the game crashes while loading mods and the FML error screen appears, because general.show_on_fml_error_screen is true.^[1][3]
3. If the analysis recognises a known crash reason, you get a dialog with a description and a solution. The first time a reason is shown, the OK button is delayed by 10 seconds so you actually read the advice (analysis.first_show_delay).^[1][3]
4. If you want help, use the Upload All button. It builds one message with links to your logs. The Request Help button opens the link set in general.help_link.^[3]

Things this pack sets

• Logs are always uploaded to mclo.gs. general.wrap_link is set to kostromdan.dev, which wraps the link and copies a short p.kdan.dev link instead.^[3]
• analysis.trigger_on_original_modpack_mods is false. When the mod runs in modpack mode for the end user, the analysis will not blame mods that were part of the original modpack, only mods you added or updated.^[3]
• The crash command is enabled (crash_command.enabled). To make sure you really want to crash the game, you have to run it again within 10 seconds (crash_command.seconds).^[3]
• general.generate_own_launcher_log is true, so the mod writes logs/stderr_stream.log with the stderr stream. Many launchers do not save that stream, and it helps with debugging some crashes.^[3]
• general.formulation_type is DISCORD, so the window's wording talks about joining the Discord and posting in a channel rather than using GitHub terms.^[3]

Unverified The mod's list of installed mods is stored in config/crash_assistant/modlist.json. The sources here do not show that file, so what it contains for this pack is unverified.

Crash Assistant has no machines, multiblocks, power, fluids or item handling. It is a client-only helper that does nothing on a server. This section covers how it behaves after a crash, and which settings the pack uses for it.^[1]

What happens when the game crashes

After Minecraft crashes, the mod shows a GUI that lists the affected game and launcher logs, crash reports and hs_err files. From there you can upload them in one click, copy the link and do other reporting actions. The GUI also supports drag and drop, so you can pull files straight out of it.^[1]

The mod can also show the GUI when the game crashes during mod loading and the FML error screen appears, which the pack leaves on with general.show_on_fml_error_screen. In this pack, general.kill_old_app is on, so an old Crash Assistant window is closed when you start Minecraft again. That way you are not confused by a window from an old crash.^[3]

A few more settings in the pack's config feed the log list. general.generate_own_launcher_log is on, so the mod writes the stderr stream to logs/stderr_stream.log, which many launchers do not save. patches.MC307905 is on too. It fixes a rare vanilla bug where generating the crash report itself crashes, and it does not change the report contents.^[3]

Uploading logs

Logs are always uploaded to mclo.gs. The setting general.wrap_link only changes which link gets copied afterwards. The config comments list mclo.gs, gnomebot.dev and kostromdan.dev as supported values, and this pack uses kostromdan.dev, which wraps the mclo.gs link and copies a short link.^[3]

The pack's config also leaves general.send_uploaded_logs_data_to_kostromdan_dev on. After an upload, the mod then sends metadata about the logs to the author's API. The log contents are not sent there, because they still go to mclo.gs.^[3]

The individual upload buttons are not enabled right after the crash. By default the mod first scans for terminated processes, since they can appear with a delay, and then enables the buttons. The pack keeps this behaviour, because general.prevent_upload_buttons_delay is false.^[3]

If a log is too large for a single upload, it is split into a head part and a tail part. For individual uploads the pack shows a head/tail selection dialog, since copied_links.skip_split_dialog is false. You can copy one part or a message with both links.^[3]

The generated message

The Upload All button builds a ready-to-post message. In the pack's config, its layout comes from generated_message.message_structure: header with upload link, custom text, the logs, the problematic frame from hs_err, the analysis result and the modlist changes. The pack puts both the analysis result names and the problematic frame into the message. Each log line gets the prefix ### and logs are separated by a vertical bar. ANSI colouring is off in the pack (generated_message.color_message is false), so the message also works somewhere ANSI code blocks are not supported.^[3]

Log analysis

The mod analyses logs for many known crash reasons. When it finds one, it shows a dialog with a problem description and a detailed solution. The reasons it covers include JVM crashes tied to GPU drivers, running out of memory, duplicated mods, Mixin errors and missing dependencies. After an upload, each supported log is also checked by the Codex analyzer from mclo.gs.^[1]

In the pack's config, analysis.enabled is on and no reasons are blacklisted. When a crash reason is shown for the first time, its OK button is delayed so you actually read the advice: analysis.first_show_delay is 10 seconds here. Also, analysis.trigger_on_original_modpack_mods is false. When the mod runs in modpack mode on a player's machine, it therefore does not blame mods that shipped with the original pack. It blames only mods that were added or updated afterwards.^[3]

The GUI menu also has analysis tools, for example one that scans for Create or Epic Fight addons incompatible with your installed version, and one that lists mods made with MCreator. The pack's config enables them with analysis_tools.enabled and blacklists no tools.^[1][3]

Modlist tracking and other features

The modlist feature is on. When the game is launched by a listed modpack creator, modlist.json is overwritten on every launch, so the creator cannot forget to save it before publishing. The creators listed in this pack are FTB Team and Saereth. You can disable the auto update and save by hand with the /crash_assistant modlist save command.^[3]

The pack's config adds the generated modlist.txt to the logs and includes the modloader jar name in the modlist. Datapacks and resource packs are not added.^[3]

Unverified The actual contents of the pack's modlist.json are not shown in the sources here. That file lives at config/crash_assistant/modlist.json, so check it there.

In the pack's config the crash command is enabled with crash_command.enabled. To make sure you really want to crash the game, you have to run it again within the time set by crash_command.seconds, which is 10 seconds in this pack.^[3]

In the pack's config, simple mode, which hides the logs behind a single button, is off. If it were on, the config's setting for modpack creators would still show them the full Expert Mode.^[3]

The help wording in the GUI uses the DISCORD formulation (the config lists DISCORD and GITHUB as the supported ones), with FTB Discord as the support name. The piracy warning is off in this pack. The Intel corrupted-processor notice and the compatibility feature are both on.^[3]

In the pack's config the scripts feature is on, along with the Scripts IDE in the GUI. The startup scripts log is added to the log list only when it contains [ERROR].^[3]

Crash Assistant is client-only, so none of this does anything on a server. Everything lives in one file, config/crash_assistant/config.toml. Most of it is cosmetic, so here are the options you're most likely to notice or want to change, with the values this version of the pack currently ships.^[1][3]

Who the crash window points you to

• text.modpack_name is currently set to "FTB Skies 2" in this pack. It fills the pack name into the window text, for example "Oops, FTB Skies 2 crashed!".^[3]
• In this pack's config, text.support_name is currently "FTB Discord" and text.support_place is "#ftb-skies-2". These feed the help button wording.^[3]
• general.formulation_type is currently "DISCORD" in this pack, so the GUI uses wording like 'join the Discord' and 'post in #channel'. The mod's other currently supported value is GITHUB.^[3]
• In this pack's config, general.help_link currently points to the FTB modpack issues repository on GitHub. That is where the request help button sends you.^[3]

Uploading logs

• general.wrap_link is currently "kostromdan.dev" in this pack. Logs are always uploaded to mclo.gs, and this option only controls which link gets copied afterwards. With this value, the mclo.gs link is wrapped through paste.kostromdan.dev and you get the short p.kdan.dev link.^[3]
• general.send_uploaded_logs_data_to_kostromdan_dev is currently true in this pack. It sends only metadata about uploaded logs, not the log contents, to the mod author's API.^[3]
• general.generate_own_launcher_log is currently true in this pack, so the mod writes the stderr stream to logs/stderr_stream.log. Many launchers don't save that stream.^[3]
• generated_message.color_message is currently false in this pack, so the message made by the Upload All button has no ANSI colors. That keeps it readable on places that don't support ANSI code blocks, like GitHub.^[3]

Analysis and warnings

• In this pack's config, analysis.enabled and analysis_tools.enabled are both currently true, and nothing is blacklisted in analysis.blacklisted_reasons or analysis_tools.blacklisted_tools. So no analysis checks are switched off by the config.^[3]
• analysis.first_show_delay is currently 10 in this pack. The OK button is delayed by 10 seconds the first time a crash reason is shown, so you actually read the recommendation.^[3]
• analysis.trigger_on_original_modpack_mods is currently false in this pack. When the mod works in modpack mode and is run by an end user, analysis won't blame a mod that was part of the original pack, only mods you added or updated.^[3]
• In this pack's config, piracy.enabled is currently false, so the piracy warning is off. Its delay, piracy.delay, is set to 10 seconds.^[3]
• too_many_changes_warning.count is currently -1 in this pack, which disables the too-many-changes warning.^[3]

The crash command and simple mode

• In this pack's config, crash_command.enabled is currently true, and crash_command.seconds is 10. You have to run the command a second time within 10 seconds to really crash the game.^[3]
• simple_mode.enabled is currently false in this pack, so the GUI does not start in simple mode.^[3]

Modlist tracking

In this pack's config, modpack_modlist.enabled is currently true, and modpack_modlist.auto_update is true too. That means modlist.json is rewritten on launch when a modpack creator runs the game. The creators are currently listed in modpack_modlist.modpack_creators as "FTB Team" and "Saereth". This setting isn't shown in the GUI, it just makes the modlist feature work correctly. The saved list itself is in config/crash_assistant/modlist.json, which is too large to reproduce here, so check that file for its contents.^[3]

FTB Skies 2: Aero 1.10.0 ships Crash Assistant 1.11.12, and the mod has been in the pack since Aero 1.0.3 or earlier. The pack changelogs have no entries for this mod, so everything below comes from the mod's own changelogs for its two most recent versions.^[4]

1.11.12

This is the version you have in Aero 1.10.0, and it is a big one for mod-list tracking and log sharing. Only the part of the changelog I could see is covered here.^[4][5]

• Mod-list history is now saved between launches. Each snapshot records whether the game only started, reached the title screen, joined a world, crashed during gameplay, or closed without a crash. The main comparison now picks a suitable previous launch dynamically instead of relying on a single static baseline.^[5]
• A new filterable, sortable two-pane browser lets you compare any two launch snapshots. Comparisons involving Current keep the Remove, Enable/Disable, Revert, Restore and Show Folder actions, while snapshot-to-snapshot comparisons are read-only.^[5]
• You can import modlist.txt data from a file or the clipboard and compare it with Current. During migration, the previous modlist.json snapshot is kept in history.^[5]
• Fixed a bug where a comparison missed an updated mod if its JAR was replaced without changing the file name or declared version. If both snapshots have a comparable CurseForge or Modrinth hash and it differs, the mod now counts as updated.^[5]
• Upload All messages now upload non-empty mod list differences and unavailable-reference notices. Generated messages link non-empty differences, keep one-line notices inline without a link, and do not upload unchanged comparisons.^[5]

Config change and the new log viewer

The general.upload_to option has been replaced by general.wrap_link. The old value is not migrated and is removed during the update. By default in the mod, copied log links now open in the new kostromdan.dev log viewer instead of gnomebot.dev.^[5]

The kostromdan.dev viewer is a fork of gnomebot.dev, tuned for Crash Assistant. Here is what it adds:^[5]

• A switcher between logs from the same Crash Assistant launch, plus a Download All button that saves every log from that launch in one ZIP archive.^[5]
• The Minecraft Profile widget uses the session UUID for logs uploaded through Crash Assistant, and shows it for every log from that launch, even if an individual log does not contain the UUID.^[5]
• You can drag across line numbers to select a range and copy a link to the whole range. Selecting a line or range copies its link automatically, and this can be turned off in the settings.^[5]
• Quick links to the first error, last error and end of the file, plus a jump-to-top button. Raw and Download are now separate buttons, and Download saves the current log as a file.^[5]
• Options to show full stack-trace locations instead of shortened ones, and to wrap long lines. Each navigation and download button can be shown or hidden individually.^[5]
• Fixed parsing and rendering of modern Minecraft stack-trace locations.^[5]

1.11.11

• Bumped JEXL to 3.7.0.^[6]
• Fixed JEXL scripts not being able to access allowed static fields of allowed classes.^[6]
• Fixed the 1.12.2 Cleanroom processor getter function after an OSHI update.^[6]
• Fixed an issue with the CurseForge API requiring an API key since July 15 to download mods from its CDN.^[6]