Many times an application may cause issues on a phone. This may not necessarily be the fault of the specific application, but more likely the data has become corrupt by the system. The first step whenever troubleshooting an Android application is to wipe all data and make a clean start.
I prefer to do this as opposed to a straight uninstall/re-install as it ensures any data which may be retained by an uninstall is also cleared. Thus you really are starting afresh. At the bottom I do link to the Play Store in case you wish to performa an uninstall as well.
This guide is a step by step 'How To' for performing this task on stock Android (KitKat 4.4.2). Whilst this is made on a KitKat device, the practice is similar for most Android ROMS.
NOTE:- Doing this procedure will wipe everything. You will need to re-login, apply your user settings and re-download any offline playlists afterwards.
1. Open up the 'Settings' from the App Drawer or from the Notification Panel.
2. Scroll down to 'Device' and select 'Apps'
3. Once the apps have loaded scroll down and find 'Spotify'
4. Open up Spotify and you'll be presented with the following screen. Press 'Force Stop' then 'Clear Data' in that order (Note: Clearing data will also clear the cache, no need to press that button).
5. Now close Settings and open the Spotify application. You will be presented with the logon screen. Log back in and re-apply any settings that you originally had.
Hopefully the above actions will be enough to resolve basic system related issues. If you are still encountering problems perform a search on the Spotify Community before creating a new topic as you may find an answer already exists for your issue.
If you want to be completely thorough, after step 4 you can then uninstall the app and do a complete re-install... Doing it this way will make 100% sure nothing remains from the original app.
To re-install you can get Spotify from the Google Play Store