In the first conversion, your original file is a TS file which contains closed captions. MCEBuddy extracts those closed captions as a SRT file but it fails to embed them since MP4Box fails.
However you have a custom profile and in your profile you instruct handbrake to look for closed captions while converting, it finds those muxed closed captions in the TS stream and automatically converted them into an embedded SRT file.
During the second conversion you start with a M4V file which the embedded SRT file, MCEBuddy extracts the SRT file and remuxes the M4V to a TS format for processing (which doesn’t contain any subtitles or closed captions), hence when it reaches handbrake it doesn’t detect anything and when mcebuddy tries to eventually put those subtitles back into the container it’s failing on your setup.
You have three options:
- Try a different computer where MP4Box doesn’t fail (it’s working here on Windows 10, 64bit)
- Enable the
Skip remuxingoption for your second conversion task (this way MCEBuddy won’t remuxed the M4V into TS and when handbrake gets the original M4V it may be able to detect the embedded SRT file and preserve it) - Modify your profile for the second conversion to instruct handbrake to use the SRT file that’s extracted by MCEBuddy along with the remuxed TS file in the temp folder and embed it into your converted M4V. Try adding
--srt-file <source_without_ext>.srtto your profilehandbrake-videoline. See inserting special commands for details on how <source_without_ext> works.