Fixing dubbing failures, timing drift, and failed exports
Diagnose and fix a dub that won't generate, subtitles that drift out of sync, or an export that stops partway through.
Updated 2026-07-23 · AutoCast v3.0 · macOS 14+
Who this is for
Anyone whose dub won’t generate, whose translated audio has drifted out of sync, or whose export stopped before finishing.
Before you start
Dubbing and export behave differently offline versus online — recording and editing work fully offline, but generating a dub and translating text both need an internet connection, since that step sends your transcript and a voice sample to AutoCast’s cloud providers.
Steps
A dub fails to generate
Check your internet connection. Recording and editing work offline, but translation and voice synthesis do not — if your Mac lost its connection mid-dub, the request fails silently and the line shows no waveform in Dubbing Review.
Check whether you’ve used up your included dubbing minutes on the Free plan. Once your Free plan dubbing minutes are used, new dub requests will fail until you upgrade to Pro.
Re-open Dubbing Review and regenerate the affected line(s) rather than the whole project — regenerating is scoped to individual lines, so you don’t need to redo lines that worked.
Subtitle or dub timing drifts out of sync
Confirm the line isn’t stuck flagged “Too long” in Dubbing Review — an unshortened “Too long” line is a common cause of drift, since the dubbed audio for that line runs longer than the original clip allows, pushing every line after it out of sync. Use AI Shorten on the flagged line before exporting. See AI Shorten for too-long lines.
If drift appears only after re-editing the timeline (cutting or rearranging clips) after dubbing, re-open Dubbing Review — AutoCast times each dubbed line to your clicks and zooms, so a change to the underlying edit after dubbing can require a line to be regenerated.
Export fails partway through
Keep your Mac awake during export, especially for long or 4K/5K videos — macOS sleep can interrupt a render before it finishes. Check Energy Saver settings, or keep the Mac plugged in and active until the export completes.
Check whether every selected language has cleared review — a line still flagged “Too long” in any language you’re exporting can stop that language’s export pass partway through. Return to Dubbing Review for that language and shorten the flagged line.
Check your Free plan export count — if you’ve already used all three lifetime exports, the export won’t run; upgrade to Pro for unlimited exports.
Retry the export after addressing the above — a partial export doesn’t count against your export limit if it never completed.
What you should see
A dub with a visible waveform for every line in Dubbing Review, subtitles and audio that stay in sync with your on-screen clicks and zooms, and an export that completes to a finished MP4 + SRT pair per selected language.
Common issues
No sound in the dub — check that Dubbing Review shows a waveform for each line; a flat line usually means the voice clone step failed silently, often due to a dropped connection. Regenerate the affected lines.
Export works for one language but not another — check that specific language’s review status; a “Too long” line only affects the language it’s flagged in.
Recording and editing work fine but dubbing won’t start at all — this points to no internet connection rather than an app problem, since dubbing is the only step in the AutoCast workflow that requires one.