Here is what they say:
**Please make sure to log into your correct JAM account, before updating to this version!**
Hey Jammers! This time we have a huge update for you. Enjoy the great advantages of BeatCoins the new virtual currency in Music Maker JAM. Update now and get 200 BeatCoins FOR FREE! Use your BeatCoins to get the newest and freshest music styles. The other good thing is, BeatCoins cannot only be bought, but also be won through contests or redeemed by finishing sessions in our new JAMCADEMY. Happy Jamming!
There seems that there was a lot of probems for people updating reading the review section on Google Play so Music Maker Jam said this:
**Please make sure to log into your correct JAM account, before updating to this version! ** Hey Jammers, we have extended our 200 free beatcoin offer for all registered users, until 29.05! We have also worked on making the app more stable.