Where is the error in the file cutting code?

Question

cmd/bat

Dropped 500 pcs. .mp4 files to the c ffmpeg folder
and wrote a code to roughly cut each video in the middle and swap the resulting 2 pieces in each video. Accuracy doesn't matter where you cut.
But the code gives an error:

2nd day I can’t understand where the error

is.

@echo on
for %%i in (*.mp4) do (
start /b /wait C:\ffmpeg\bin\ffmpeg.exe -i "%%i" -map 0:0 -map 0:3 -map 0:2 -acodec copy -vcodec copy "%%~ni".mp4
)
pause