In the folder where you have these video files: delete the .idx2 files with the same names.
Load the 1st video, if avidemux asks to load remaining videos: answer no.
Append video 2: Avidemux Menu: File Append
Save the new video "New1": does this work?
- The previously edited 1st video does not end with a keyframe.
- Close files
- Load 1st video, go to the end of the 1st video.
- Once keyboard Up Arrow, Once Keyboard Down Arrow. Mark no only with [ B].
- Save video Test1
- close videos
- load video "Test1". Append video 2: Avidemux Menu: File Append
- Save the new video "New1": does this work?
the videos are all from the same source? (cam, recorder, ... ) Important: not from the internet downloaded