mp4v2 muxer do not save 4k video only mp4muxer

[marava]

in Ubuntu 22.04 using Avidemux (2.8.1 appimage) I have cutted a 4k mp4 video. If I try to save it without re-encoding using mp4v2 muxer i receive an error. If I use mp4 muxer it is all ok. It is a correct behavior an why?
The file characteristic  are MP4, hevc Main@L6@Main, 99.9 Mb/s, 59.940 (60000/1001) FPS

[szlldm]

despite the misleading naming, the mp4v2 is obsolete (AFAIK)
if the desired output format is mp4, then the plain "mp4" option should be chosen.

[eumagga0x2a]

Video resolution is not the problem, the MP4v2 library simply doesn't support HEVC.

The dead MP4v2 project was forked and thus revived recently, albeit the last change is 5 months old as of writing. There have been a lot of fixes for security and stability issues as well as for memleaks, but few (if any) new features, i.e. no support for HEVC yet. The old version shipped with some Avidemux builds is deprecated and should not be used, its sole purpose was to create files compatible with some now obsolete Apple iDevices. Back then, Apple's devices expected some metadata (as placeholders) to be present which the libavformat-based MP4 muxer didn't add to MP4 files.

As szlldm told you, don't use MP4v2.