If I click on the option WebM/MP4/MKV/OGV with audio, animation number of sections cannot exceed 60 or the animation video will not be successfully produced, I tried 4 engines and all failed.
I switched to another computer with different hardware specs, Failed again. So I think this should be a software problem.
Without adding audio, I can turn it up to the animation number maximum of 100, no problem. With audio...... Only 60