FFmpegPostProcessorError: Last message repeated 1 times

[peterwillcn]

[download] Destination: 4K VIDEO ultrahd hdr sony 4K VIDEOS demo test nature relaxation movie for 4k oled tv-Bey4XXJAqS8.f251.webm
[download] 100% of 29.94MiB in 00:24
[ffmpeg] Merging formats into "4K VIDEO ultrahd hdr sony 4K VIDEOS demo test nature relaxation movie for 4k oled tv-Bey4XXJAqS8.mp4"
[debug] ffmpeg command line: ffmpeg -y -i 'file:4K VIDEO ultrahd hdr sony 4K VIDEOS demo test nature relaxation movie for 4k oled tv-Bey4XXJAqS8.f313.webm' -i 'file:4K VIDEO ultrahd hdr sony 4K VIDEOS demo test nature relaxation movie for 4k oled tv-Bey4XXJAqS8.f251.webm' -c copy -map '0:v:0' -map '1:a:0' 'file:4K VIDEO ultrahd hdr sony 4K VIDEOS demo test nature relaxation movie for 4k oled tv-Bey4XXJAqS8.temp.mp4'
ERROR:     Last message repeated 1 times
Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 2051, in post_process
    files_to_delete, info = pp.run(info)
  File "/usr/local/bin/youtube-dl/youtube_dl/postprocessor/ffmpeg.py", line 506, in run
    self.run_ffmpeg_multiple_files(info['__files_to_merge'], temp_filename, args)
  File "/usr/local/bin/youtube-dl/youtube_dl/postprocessor/ffmpeg.py", line 232, in run_ffmpeg_multiple_files
    raise FFmpegPostProcessorError(msg)
FFmpegPostProcessorError:     Last message repeated 1 times