Can't remove # filter from music directory

[Hinginator]

Can't edit # attribute in View->Choose Details

I can't remove the track number (#) filter from my music directory. I've been using MP3Tag to sort out my files. I think the problem might me because the files are MP4's. I'll attach some photos to explain.

 

[ignatzatsonic]

I can't even open a file with an mp4 extension in mp3Tag. You're asked to "select a directory that contains audio files", so mp4s aren't even shown. At least on my PC.

 

[ShoTTaS]

There should be "more" option at the bottom part of the drop-down-list.
On the next pop-up window. Move down the # , make the Name/Title to be on top. uncheck the #. it will disappear surely.

Regards