Bug Report: H.264 Export Fails on All Projects (Selector 9, Error Code 3)

Summary

H.264 export fails consistently and immediately (within the first 1-2 seconds of encoding) on every project tested, including a brand-new project with a single random clip and no effects. QuickTime/ProRes export from the identical source completes successfully every time. This isolates the failure to the H.264 exporter component itself rather than any project, sequence, or media content.

Environment

• Mac model/chip: Apple M2
• macOS version: [fill in — Apple menu > About This Mac]
• Premiere Pro version/build: [fill in — Help > About Premiere Pro]
• After Effects version/build: [fill in, if relevant]
• GPU acceleration setting: Video Rendering and Playback renderer selector is grayed out/locked in Project Settings > General
• Storage involved: Local internal SSD (issue persists even with no external/network drives involved)

Steps to Reproduce

1. Open Premiere Pro.
2. Create a brand-new, empty project.
3. Import a single video clip with audio.
4. Drop it on a new sequence with default settings.
5. Export via File > Export > Media.
6. Select H.264 format (reproduced with both a default preset and the "Vimeo 1080" preset).
7. Click Export.

Result: Export reaches approximately 0-3% and fails with the error below, typically after a multi-minute hang at 0%.

Error Message

Error compiling movie.
Export Error
Error completing render.
Writing with exporter: H.264
Writing file type: H264
Around timecode: 00:00:01:08 - 00:00:01:25 (varies slightly by attempt)
Component: H.264 of type Exporter
Selector: 9
Error code: 3

This same error and a near-identical early timecode occurred across:

• The original full-length project (multi-track, Dynamic Link to After Effects present)
• A duplicated copy of that sequence with the Dynamic Link layer fully deleted
• A 16-frame export of completely empty/black timeline space
• A brand-new test project with one unrelated clip and no effects

What Has Been Ruled Out

The following were each tested in isolation and do not resolve or explain the issue:

• Closing After Effects completely before exporting
• Disabling the Dynamic Link layer / deleting it entirely from a duplicated sequence
• Exporting from a completely empty section of the timeline (no clips, no effects)
• Disabling "Enable hardware accelerated encoding/decoding" in Preferences > Media
• Clearing media cache and media cache database (hosted on a fast local external SSD, not network storage)
• Disabling Content Credentials in export settings (this resolved a separate, earlier hang at "Preparing Content Credentials... 100%", but did not resolve the H.264 export failure itself)
• Moving export destination from a LucidLink-mounted volume to local storage
• Testing in a brand-new project with new, unrelated media

What Reliably Works

• QuickTime / ProRes export succeeds without error, using the same source clip(s), same machine, same session.

Suspected Cause

Given that:

• The failure is 100% reproducible across unrelated projects and content,
• It occurs almost immediately in the encode (within the first ~1-2 seconds of output timecode),
• GPU/Video Rendering renderer selection is locked/grayed out in Project Settings,
• QuickTime export (different underlying codec path) succeeds every time,

this points to a broken or corrupted H.264 encoder component in this Premiere installation, possibly related to how it interfaces with VideoToolbox/hardware encoding on Apple Silicon (M2), rather than anything project- or content-specific. This may be a regression introduced by a recent macOS and/or Creative Cloud update — the issue began appearing after updating Premiere Pro, After Effects, and macOS to their current versions.

Current Workaround

Exporting ProRes/QuickTime from Premiere, then converting to H.264 via a third-party tool, as Media Encoder's H.264 path is suspected to share the same broken component.

Request

Please advise whether this is a known issue with the current Premiere Pro build on Apple Silicon, and/or provide steps to repair the H.264 exporter component specifically without a full application reinstall.