Since a few days offline purchasing seems to be broken somehow. I have 0.44 Credits on my account so I am not able to take it back as metal. But everytime I try to buy something using the credits system the message "Checking backpack visibility, please wait a few seconds" appears and won't go.
Please help me or fix. :S

Actually, the offline purchase would not work for users without a shop (there is no place to temporarily store your item). You have discovered a flaw on our offline purchase. We will find a way to improve this.

For the time eing, you can make a shop to receive your offline purchase items.