Teamlava forums have an existing thread on this:
http://forums.teamlava.com/showthread.php?17453-quot-We-were-unable-to-send-the-material-to-your-friend-quot-message
It looks like mostly the Iphone/Ipads were affected. I have an android and do not have issues sending materials.
What I have noticed is that I no longer get messages saying that someone has accepted over 20 materials a day.
Anyhow - feel free to add your device and information to the thread above and stay tuned for a new update to the game!
