It says in the forums/FAQs that m4a files are taggable, and yet every time I try to change my track numbers from 1,2,3,4 to 01,02,03,04 they come back as 1,2,3,4, Do I need a plug in or what?
Mp3tag does not support plug-ins.
And M4A files do not support leading zeros for track numbers.
Trying searching the forums: M4A track.
Start here: Not possible to save track numbers with leading zero in m4a