Solution:
The description of the manufacturer is in fact flawed, so WRONG !!!
The SIM card must (not down) are inserted and the missing corner to the inside with the contacts facing up. The card must be really pushed to the stop. The fatal thing is that the card already clicks on the short way and then see about 2 mm [this does not work!]. If necessary, use a thin object to really "sink" the card in the device to. Then it will come.
Otherwise, very good workmanship and features. It is easy because of the price / performance ratio TOP!
Point deduction because of obviously well-known lack of description. Himself had the first Tablet returned as defective and immediately get a new - of course with the same problem.
Only my "extensive" research on the Internet took me to the track because the customer only Mon. is achievable and I am the second tablet on Friday afternoon received !!!.
It would be about time that the manufacturer solves the known problem elegantly!