I tried your advice, but it didn't work. Then I remembered installing Icaros recently, to help with viewing MKV properties. I uninstalled Icaros and my problem is solved. Thanks anyway for your advice.
Sorry. I use the latest version of MPC-HC. I've been using it for years. I edit my mp3's by right clicking, then Properties/Details. I can't edit any info there, any longer. I could try a 3rd party app, but I'd like to figure out why I can't do it the usual way.
I just upgraded from Windows 10 to 11. I know have two accounts on my PC. One is my account and on the other is Administrator. When I go to Accounts, Other users, only mine show up, not the Administrator account.