It looks like ffmpeg is having trouble processing the file while converting it
2021-02-12T21:32:20 MCEBuddy.AppWrapper.FFmpeg → [mp4 @ 0000021b5d458100] Cannot write moov atom before AC3 packets. Set the delay_moov flag to fix this.
2021-02-12T21:32:20 MCEBuddy.AppWrapper.FFmpeg → Error writing trailer of D:\MCEBuddy2x\tmp\working0\Anderson Cooper 360_CNNHD_2021_02_12_19_58_00-converted.mp4: Invalid argument
Can you upload a copy of the original WTV video to our sever so we can replicate it and see what’s going on. Welcome to MCEBuddy - README BEFORE POSTING