I figured it out, even though the error message was not informative, it worked out to be the Codec and Container. (4K) I switched from H264/mp4 to H265/mkv and it works just fine, strangely, the preview vids are H264/mp4 files.
Looking at the logs I am seeing a file path error, that the app can not open the output location.
Double check where you are exporting the video to and confirm that the file path is good and that the app has access to that drive in case its an external drive.
If the video is above 4k resolution you will need to swap to H265 from H264 as it is above the resolution size that H264 can handle.