Why Mp3Tag won't let me select files and drag into an iTunes playlist?

Does anybody know this?
At times the shitty itunes will allow me to drag selected files in Mp3tag over to one of its playlists, sometimes it won't.!!!
It's so effing annoying.

Not sure whose fault it is this time, probably itunes for a change.
Though to be honest I can always drag tracks from iTunes into Picard, but from Mp3tag into itunes it doesn't work always, it's kinda random.

I don't know this. But if if works sometimes and sometimes it does not it is down to your investigative skills to find the differences in the process.
Perhaps some of the files are already in the iTUnes library and others are not (perhaps because you renamed them)...

Thank you for the attention, what I've realized was that at times you have to hang on a bit with the selected files over itunes for it work.
If it's few files, that happens quickly, if it's a lot, it can take some time.
So, maybe that's what confused me, it should always work, provided that you wait long enough with the files selected, and dragging into itunes and waiting.