Sharing playlist - confusion

[MarkRG01]

Hi all, I have Spotify premium on an andriod device (HTC One m8) and getting very confused trying to share a playlist with a friend. Neither of us are on facebook, she is listed as a friend on spotify and, it looks as though we are both following each other too. However, I select a playlist, long press to bring up a menu and select share form the options and then spotify friends, I get a panel asking me to fill in a few details starting with To:  I type in her spotify name and then a message but the 'Send' button remains greyed out. So I try writing her name as spotify:user:hername and 'Send' is still greyed out.  I am trying this while connected on WiFi. I am not sure if she has a premium account - would it make any difference?

If I use my computer at home I can share songs and playlists with her no problem so what am I doing wrong on my phone? 

For info, settings on the phone are:

Offline mode is off

Device broadcast is off

Private session is off

Spotify version is 0.7.9.1170

Android 4.4.2

HTC Sense 6.0

[Joe]

Unfortunately, Spotify sharing is only possible between facebook friends on the mobile app. You can, however, share via other means, such as email or SMS.

[MarkRG01]

Thanks. That would explain it. Seems like an odd restriction to make. Also, the app ought to do more than simply grey out a button and leave users to guess what it might mean. A message about only being able to share with facebook friends would be useful. Hey ho.  

[Joe]

Oh, providing helpful and meaningful error messages to users has never been Spotify's strong point 😞