iPhone not showing up on computer

[Mister13]

I usel to be able to sync my local files to my iPhone. Then something happend months ago, and my local files were gone. Now you no longer can connect via cable, why? Now it's only possible connecting The computer and iPhone to The same wi-fi, which isn't working for me. I've tried all The basics uninstalling on both computer and iPhone (6). I've read alot of posts here and nothing helps, i have no firewall blocking Spotify. I've emailed Spotify with screenshots on my screens to get some help, i got no reply. Hope some 1 can help me. I can play my local files on my computer and add them to my playslists but on my iPhone it says i have no local files. In my playlists The local files i add on The computer and then try to play on my iPhone it pops a 'learn more' or 'cancel' choice. If i press learn more it says that connect to The same wi-fi bull.
Please help, going cray here.