Chosen Solution
Why error activation after chang Serial+Wifi+Bluetooh address iPadAir 11.4.1, serial is buyed in paidunlock.com
Because the security CRC value does not match. You can’t change the assigned serial number and MAC address. This is why you can’t reprogram an iPhone or iPad as Apple did a very good job making it very hard to steal. Best thing here is get your money back and sell this iPad for parts.
