Answer
The BL600 license key is a unique number assigned to each BL600 module. It is tied to the random MAC address which Nordic etches into the silicon of the Nordic chip. Laird’s firmware takes that random number and matches it with the license that we program at production time.
If the license key does not match or it does not exist, the firmware operates with reduced transmit power (~4 dBm) and the autorun program in the BL600 flash memory will not run.
For these reasons, it is extremely important that you restore the BL600’s license key after you upgrade the module firmware.