Rovio has fixed the problem already on iOS, but Android is another story.
The update, which makes Tiny Thief free-to-play with a brand new premium episode, has caused some users who already purchased the game to be notified that they need to do so again, Rovio wrote on its blog.
On iOS the company has already released a second update to patch the error, but the solution on Android is not so forthcoming, because "for technical reasons, the purchase history cannot always be restored on that platform," Rovio said. Players on Android should email firstname.lastname@example.org if they experience this glitch.
"Our apologies for any inconvenience caused by this issue, our support team is ready and waiting to help get this sorted out so you can continue the Tiny Thief adventure!" the company wrote.