I've edited tag some mp3 files by foobar2000, then wmp and itunes can't read their tag but Mp3tag still can read. Please tell me how to fix. Thx
check whether your mp3s are still ok with a program like mp3val (freeware).
Others in this forum have other preferences program-wise - it is your choice.
foobar default tag for mp3 is ID3v2.4. That is probably your problem. Either in mp3tag or foobar, set the tagging option to ID3v2.3 (in foobar this is called "compatibility mode"). Then resave the files/tags. You can do all this with a couple of mouse clicks for all your files. Test on a few first to make sure you're getting the outcome you expect. ID3v2.4 often creates issues with lots of players. You are safest with v2.3.
edit: and make sure you didn't accidentally save as APE or some other non ID3v2 tag.
thanks you very much