H.264 exporting file corrupted

When I export h.264 mp4 files from After Effect with Media Encoder, the files that are created are corrupted, I can only preview part of them and many video player programs do not recognise them. I have tried from different terminals with the same version of Media Encoder and the problem remains.

iMac 2019 OS 10.15.7 - AE 18.0 - ME 15.0