I'm having a problem very similar to the one herb clark described. It occurred when I upgraded to OSX 10.10. Suddenly have the songs in my itunes library have this **** exclamation point in front of them and they don't play in a playlist. I can play them by simply double-clicking on the song, this will clear the exclamation mark and start playback. I can also clear the mark by selecting the song and choosing "Get Info"—as soon as the info window opens the mark disappears. Once the mark is gone the song then behaves normally and plays in the playlist.
It has nothing to do with deleted files. No files have been deleted. Itunes never asks me to locate files.
I have not synced with any devices. I have never synced itunes.
I doubt it has anything to do with itunes Match because I've never used Match or subscribed to it.
It appears that the only way to fix this is to doubleclick on every song that has an exclamation mark. That would take hours to do.
Any ideas about how to fix this and make the exclamation marks go away?