Copying files doesn't convert them, what version of MediaMonkey and Codec?

I had that happen to all my 5 star AAC's when I tried transcoding them to MP3, (copy to, not convert to)... trashed all of them. I backed out the version of MM and the MM_Codec and reinstalled an older version, but the damage was done. Had to restore all of them from either backup or re-download from iTunes. To the best of my testing the latest version and newest Codec don't seem to cause any problems. Your mileage my vary.

Which File Type(s) are affected?

I Just started MediaMonkey today and when I try to play a song they all start to gray out. I will eventually get a message about a missing codec and the link takes me to something for quick-time. I can play the same song in Windows Media Player or VLC player. I tried uninstalling and reinstalling Media Monkey with same issue. I searched around and some people said Windows Media pack needs to be updated. Win 10 ver 1909 I dont seem the ave that in my apps and features, and cant seem to find a download for the 1909 version. Also, my default player was Groove when started today. I changed it to Mediamonkey but it still didnt help.