appended 2 mkv (x264) files with same setting but appended minutes are grey

[ben45]

Hello
I have appended 2 mkv files with identical setting but appended minutes are grey.
The only diffrence Between files is encoder version
Original file

Writing library : x264 core 135 r2 f0c1c53

encoded file

x264 core 148 r2638 7599210

help please

[sneaker]

Use search, e.g. for ffmeg concat demuxer. MediaInfo only shows basic differences. There's more to see using a tool like CodecVisa.