downloads partial files from youtube, missing either video or audio

Have activated 4k v4.10.1.3240, Win10.64b
Downloaded a (large) batch of music videos, in high quality. Some have no issue. Some have partially missing audio streams. Some have partially missing video streams. In a large batch, I must review EACH download, if it is "bad" must manually re-initiate download. This defeats the purpose of automated software.