iTunes can't locate files except manually
I'm sure others have had this problem, though I couldn't find it in previous posts (many are very similar). I keep my music files on an external hard drive. In the past, if I forgot to plug in the drive and tried to play a song in iTunes, I'd get a exclamation point by the file. Sometimes it would put an exclamation by all files. Usually, though, I would manually find one file and it would find all the other I had in that folder. I've been doing this for a year, using iTunes frequently with no trouble. Today, non of the songs have exclamation points by them until I click on them so none of them are searched for except manually. Eventually, I had the idea to put all of my songs into a playlist, which made iTunes realize it couldn't find them, so now they all have exclamation points, but locating one file does not point iTunes to the rest. I changed the iTunes media folder location to the external hard drive, though my music is in two folders on this drive. Nonetheless, even within a given folder, iTunes doesn't automatically find all other missing files the way it has in the past. Thanks in advance for your help.