Another reason is a Copyright infringement (will give the exact same error). I also had videos who finished uploading, shown "Video published" but did not appear on my channel - again, copyright infringement.
Dailymotion video codecs https://faq.dailymotion.com/hc/en-us/articles/115009030568-Upload-policies-technical-specifications
I'm also showing my settings for OBS Studio screen video recording so it can be uploaded on Dailymotion without error.
