Help me i dont understand the issue

[Moe786R]

[ERROR] Error: Command failed: ffmpeg -i "C:\Users\User101\Desktop\New folder\destreamer-v3\videos\video-8728-vjCLWOfIBFIN\FASSET - FAC2601 (Exam May 2020) - 2020-09-13 #8b058c78.mkv.video" -i "C:\Users\User101\Desktop\New folder\destreamer-v3\videos\audio-8728-t1PKE1V83kWk\FASSET - FAC2601 (Exam May 2020) - 2020-09-13 #8b058c78.mkv.audio" -c copy "videos\FASSET - FAC2601 (Exam May 2020) - 2020-09-13 #8b058c78.mkv"
at checkExecSyncError (child_process.js:611:11)
at Object.execSync (child_process.js:647:15)
at Object.childProcess.execSync (pkg/prelude/bootstrap.js:1507:30)
at downloadVideo (C:\snapshot\destreamer-aria2c_forRealNow\build\src\destreamer.js:257:25)
at runMicrotasks ()
at processTicksAndRejections (internal/process/task_queues.js:97:5)
at async main (C:\snapshot\destreamer-aria2c_forRealNow\build\src\destreamer.js:300:5)

[FATAL ERROR] Unhandled error or uncaught exception!
Please check your download directory/directories and try again.
If this keep happening please report it on github "https://github.com/snobu/destreamer/issues"