How to Fix Alight Motion Black Screen & Export Crashes (2025 Guide)

Why Is Your Export Failing at 99%?

To fix the crash, you need to understand what is happening inside your phone.

The “RAM Bottleneck” Explained

Alight Motion is a professional compositing tool. Unlike simple editors, it renders every pixel in real-time. When you hit “Export,” your phone’s processor (CPU) and graphics chip (GPU) hit maximum load.

• The Crash: If your project demands 4.1GB of RAM but your phone only has 4GB, the system kills the app to prevent the phone from freezing. This usually happens at 99% because that’s when the heaviest compilation occurs.

H.265 vs. H.264: The Hidden Codec Conflict

This is the cause of the “Black Screen” (audio but no video).

• H.265 (HEVC): The default setting. It compresses video heavily to save space but is very hard for older phones to decode.
• H.264 (AVC): The older standard. Larger file size, but compatible with everything.

Solution 1: The “Video Codec” Fix (The #1 Cause of Black Screens)

If your video exports but plays as a black screen, or if you get an “Encoder Error,” this is the fix.

How to Switch from H.265 (HEVC) to H.264 (AVC)

Alight Motion hides this setting in a submenu. Here is how to find it:

1. Open your Project and tap the Export Icon (Top Right).
2. Do not click the big “Export” button yet.
3. Tap the small Arrow (>) next to the word “Video.”
4. Scroll down to “Codec”.
5. Change the selection from H.265 (HEVC) to H.264 (AVC).
6. Tap Export.

Why H.264 Fixes the “Black Video” Glitch

Many Android media players (especially on budget devices from Xiaomi, Realme, or Infinix) do not have the hardware license to play H.265 files. By switching to H.264, you force the app to create a universally compatible video file. It might be 10MB larger, but it will actually work.

Solution 2: Optimizing Export Settings (Stop Crashes)

If your app crashes back to the home screen during export, your project is too heavy for your RAM. We need to lighten the load.

The “Safe Mode” Export Settings (720p / 30fps)

I know you want “4K 60fps” quality. But a 720p video is better than no video.

1. Open Export Settings.
2. Resolution: Lower it to 720p HD (or 1080p FHD if you were on 4K).
3. Frame Rate: Lower it to 30fps.
   • Why: 60fps requires rendering twice as many frames per second. Dropping to 30fps cuts the workload in half instantly.
4. Quality Slider: Set it to Medium (around 8-10 Mbps).

Why You Should Turn Off “Export to Gallery” Initially

After exporting, Alight Motion tries to save the file to your gallery immediately. Sometimes, this “Write” permission causes a crash.

• Tip: Instead of “Save to Gallery,” try clicking “Share” and sending it directly to Google Drive or WhatsApp. This bypasses the gallery indexing process.

Solution 3: Fixing “Preview Lag” While Editing

Is your Alight Motion Black Screen happening while you are editing? Does the preview freeze when you press play?

How to Enable “Low Quality Preview” Mode

This setting forces the app to show you a pixelated version of your edit while you work, saving 90% of your GPU power. The final export will still be full HD.

1. Open your Project.
2. Tap the Gear Icon (Settings) at the top right of the timeline.
3. Find “Preview Quality”.
4. Set it to “Low” or “Very Low”.

Disabling Motion Blur & Heavy Effects

Motion Blur is the heaviest effect in the app.

• The Workflow: Turn the “Eye” icon (Visibility) OFF for all Motion Blur effects while you edit. Only turn them back ON right before you export. This prevents the app from trying to calculate blur physics every time you move the playhead.

Advanced Fixes: When Nothing Else Works

If you have tried everything and it still crashes at 99%, your project might be corrupt.

The “Split Project” Trick (For Long Edits)

If your video is 30 seconds long, your RAM might fill up by second 25.

1. Duplicate your project in the project list (Long press > Duplicate).
2. Open Copy 1: Delete the second half (15s – 30s). Export the first half.
3. Open Copy 2: Delete the first half (0s – 15s). Export the second half.
4. Create a new project and stitch the two exported videos together.

Identifying the “Culprit Layer” (Corrupt Media)

Sometimes, one specific image or video file is corrupted.

1. Turn off the visibility of your top layer. Try to export.
2. If it crashes, turn it back on and hide the next layer.
3. Repeat until the export works. The layer that was hidden when it finally worked is the “Corrupt” one. Delete it and re-import that file.

Troubleshooting Specific Error Codes

Fix “AVFoundationError” (iOS)

This is an Apple-specific error related to audio.

• Fix: Convert your audio file. The .mp3 or .wav file you are using might have a variable bitrate. Use an online converter to save it as a standard AAC or MP3 (Constant Bitrate) file and replace it in the project.

Fix “Encoder Init Failed” (Android)

This means your phone’s hardware encoder refused to start.

• Fix: Restart your phone. If that fails, go to Alight Motion Settings (Home Screen) > About > Three Dots > Re-evaluate Video Codec Performance. Let the app re-scan your hardware capabilities.