Comp: 1.mp4

Avoid direct H.264 exports from After Effects. Instead, render to a high-quality format (like Apple ProRes or DNxHD) and convert to .mp4 later.

Pre-compose all layers so only one layer exists in the timeline. Comp 1.mp4

Knowing these details will help me provide a specific solution to get your render finished. H.264 exporting error - Adobe Community Avoid direct H