Aegisub Keeps Crashing? Causes and Fixes for Mac & Windows (2026)

TL;DR: Most Aegisub crashes come from one of three things — loading a video or audio file its media provider can't decode, a corrupted config folder, or (on Mac) an unsigned build that macOS blocks on launch. The fastest fixes are switching Aegisub's audio/video provider, resetting its config folder, and updating to the current v3.4.2 build. If you only used Aegisub to create, translate, or burn in subtitles — not for ASS karaoke typesetting — a maintained tool that doesn't load fragile media providers avoids the problem entirely.

Aegisub is still one of the best manual subtitle editors ever made, and it's actively maintained again after a long quiet stretch. But crashes remain common, especially on Mac. This guide walks through the specific causes and fixes, in the order most likely to work.

Why Does Aegisub Keep Crashing?

Aegisub loads video and audio through separate media provider libraries, and does most of its heavy work in the desktop UI. Nearly all crashes trace back to one of four things:

• The video provider can't decode your file: opening a video with an exotic codec, variable frame rate, or a broken index makes Aegisub freeze or crash — a long-standing, well-documented issue (crashes when opening a video, macOS crashing while working with video).
• The audio provider fails: audio going silent after a minute or two, or crashing on files with multiple audio tracks, is a known problem — sometimes tied to newer macOS versions (audio issues on newer macOS, audio troubleshooting).
• A corrupted config folder: if Aegisub crashes on startup or right after a specific action, and reinstalling doesn't help, the problem is usually the saved preferences — reinstalling keeps them.
• Mac: the build is unsigned: the official macOS download isn't notarized (Apple denied the developer's account), so Gatekeeper blocks or immediately quits it on first launch. It reads like a crash, but it's a security block.

Fix: Aegisub Crashes When You Open a Video

The video provider is the single most common crash trigger. Instead of feeding your original file straight into Aegisub, try these in order:

• Transcode to a clean, Aegisub-friendly file first. Re-encode to constant-frame-rate H.264 in an MP4 or MKV container with ffmpeg or HandBrake, then open that. Variable frame rate and unusual codecs are the usual culprits.
• Work against audio only. If you just need timing, skip loading the video entirely and time against the audio waveform — this avoids the video provider that's crashing.
• Use a dummy video. Video → Use Dummy Video gives you a blank reference track for timing without decoding a real file.

Example ffmpeg command to produce a safe file: ffmpeg -i input.mkv -c:v libx264 -vsync cfr -r 24 -c:a aac output.mp4

Fix: Crashes or No Sound When Loading Audio

If Aegisub crashes when opening audio, or the sound cuts out after a minute or two:

• Switch the audio provider/player in Preferences → Advanced → Audio. If the current player crashes or goes silent, a different one often works.
• Open a separate WAV instead of "audio from video." Extract the track to PCM WAV (ffmpeg -i input.mp4 -vn -acodec pcm_s16le audio.wav) and open that file. Multi-track audio embedded in video is a frequent crash source.
• Lower the audio cache in Preferences if you're working with very long files — cache handling has been linked to crashes on large media.

Fix: Reset a Corrupted Aegisub Config

If crashes survive an uninstall/reinstall, your preferences are corrupted. Quit Aegisub, then rename or delete its config folder — Aegisub rebuilds a clean one on next launch:

• Windows: %AppData%\Aegisub
• macOS: ~/Library/Application Support/Aegisub (older builds also used ~/.aegisub)
• Linux: ~/.aegisub or ~/.config/Aegisub

Rename it first (e.g. add .bak) rather than deleting, so you can restore your styles and settings if the reset doesn't help.

Fix (Mac): Aegisub Won't Open or Quits on Launch

On Mac, "Aegisub can't be opened" or an instant quit on first launch usually isn't a real crash — it's Gatekeeper. The official macOS build isn't notarized by Apple, so macOS blocks it by default.

• Right-click the app → Open, then confirm the dialog. You only need to do this once.
• Or go to System Settings → Privacy & Security and click Open Anyway after the first blocked attempt.
• On Apple Silicon, use the current native build — old Intel-only builds running under Rosetta were far less stable.

Fix: Update to the Current Aegisub Build

Many crash reports online predate Aegisub's rebuild. The project returned with v3.4.0 (December 2024) and v3.4.2 (January 2025) on a modern cross-platform UI, with official macOS builds including Apple Silicon. If you're on a 2014-era build or an old community fork, update first — it fixes a large share of legacy crashes on modern systems.

When Aegisub Isn't Worth the Fight: A Maintained Alternative

If you rely on Aegisub for ASS karaoke effects and advanced typesetting, keep it — nothing else matches that, and it's worth troubleshooting. Be honest with yourself about what you actually use it for, though.

Most people hitting these crashes are trying to do something simpler: turn a video into subtitles, translate them, or burn them in. If that's you, GeekLink handles that path without the fragile media-provider setup that makes Aegisub crash — you import a video and it transcribes, OCRs hardcoded subtitles, translates, and burns in, from a notarized Mac build with no Gatekeeper block.

GeekLink is not an ASS typesetter — it does basic styling (font, color, size, position, shadow), not karaoke override tags. It's the better fit when your job is generating and translating subtitles rather than hand-crafting effects. See the full Aegisub vs GeekLink comparison.

Disclosure: GeekLink is our product. Aegisub is a pioneering, still-excellent tool that shaped subtitle editing for a generation — we respect its legacy. This guide reflects the state of both tools in 2026.

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