Cubasis LE 2 unable for in-app purchase

Hi everyone.
I’m currently using Cubasis LE2 on iPad3 in demo mode and I’m unable to upgrade to Cubasis 2 full feature via in app purchase using season sale (14,99): there is available only a “restore purchased” button which - of course - sends me “no past purchases” messagge.
I don’t know what I’m doing wrong.

Thank you for your help.

Hi Masnado,

Cubasis LE 2 requires to be unlocked via a compatible hardware device first, before in-app purchases are accessible from within the in-app store. Unless unlocked, Cubasis remains to run in demo mode.

Here is the list of compatible hardware devices to unlock the app from demo mode: