Can't append mp4 files using Mp4v2 muxer?

[chumbo]

Hi,
Complete newbie here. I want to append two videos so I followed the simple instructions to do so and since I see my original files are in mp4v2 format, I figured it would make sense to use that as an output as well. However, when selecting mp4v2 from the Output Format drop-down menu and saving, I get an error.
It doesn't happen with the mp4 or mkv muxer so...any thoughts, maybe this is normal? Dunno.

I'm using a portable version of avidemux, distributed by portableapps.com, maybe that has something to do with it?
Thanks!
Chumbo

[eumagga0x2a]

It would be helpful to know what the error actually was and which particular version of Avidemux was packaged as portable that you were using.

[Jan Gruuthuse]

You could try to update Avidemux portable:
more info can be found here: AQUAR: "ADM can be used as a "real portable" where it doesn't use the windows data folder but stays in the local installed folder"