Not sure, I have seen other issues that sound somewhat similar but mine might be a little more unique, or maybe they just didn't give as many details as I am about to.
So I have become pretty attached to EZ Folder Player as it is extremely simple yet functional, and at first I thought it was an issue with the app. But in my disappointment of it not working and the fact I use my phone to jam chunes a lot, I started desperately looking for another app with comparable features. Well as it turns out, I have installed other players, but PlayerPro has the exact same behavior as EZ Folder Player did, so I have to assume it is a larger issue with ICS and not just the app itself.
So the issue is this, I can browse to my external SD storage just fine with a any one of the file browser apps I have. Yet when I go to browse for a music library in either of the above mentioned apps, all I get in the file browse popup is a '/' with no window content showing my files. And I can't browse anywhere or do anything, it just shows the slash and all I can do is hit back.
I need to be able to access /mnt/sdcard-ext/musics to access my library, but all I can get to is / so I am stumped. It's weird because the app Clean Music Player will browse my music fine, but nothing else does. I am guessing must be something in the way it accesses the data. And yes, since it was the only tip I could find I already hit clear data on the media storage app service. Didn't help.
To give some background, I had done the OTA update to my Droid 4 going in-place from GB to ICS. I did have it rooted but that got broken on upgrade, though I found an ICS rooter and all was well. But I didn't listen and do a factory wipe right after the update. After a few months of some issues and bugs, I finally wiped it a couple days ago and decided to just start from scratch so I could make a nice clean backup with Titanium. Now here is the clincher, I just guessed on this and maybe should have researched (IE I am guessing this could be root cause) is that Titanium told me it detected that my Android Device ID had changed, probably due to a recent wipe. It asked me if I wanted to import the old one or keep the new one. I should have probably just let it use the new one, but I chose to import the old one afraid I might lose access to my sd card. Guess I picked wrong.
So yah if anyone knows a good fix for this I would love to hear it, otherwise I have to wipe and start over AGAIN and with all the apps I have now this takes FOREVER! Thanks Guys!