Yellow font in Playist

[akilleas]

I have a playlist with about 1200 songs, all songs are in the same folder.
Particular one of them is listed with yellow color font and it is not playable.
I tried deleting it from this folder and copying it back again from another folder with no luck.
If I add it straight from the other folder, everything is fine.
Why does it happen?

Thanks in advance!

[dro]

You've set it to be excluded from playback. Select & use alt+x or do it via the excluded files window.

[akilleas]

Thank you so much!! That was it!