I have a iphone 5s running on the latest IOS8 version & Spotify version 18.104.22.168.
Ever since the new IOS8 came out my offline albums or anything won't show up when you go into the album section. Its just a blank playlist area with the 'Available Offline' button click on yes, shuffle play button does nothing.
To make things appear you have to go into settings playback, untick offline mode and then go back to the album you want to listen to, 3G then loads the album as normal (with the avalible offline icons next to each song) and then go back to press the offline mode back on... which then it works. But I have to do this everytime.
Basically: Offline 'anything' wont show up in offline mode.
I've uninstalled the app twice, works about a day then goes back to this system.