Those days,same of my customers told me that after activate the MB SD C4 ,the next time,it need activate again.
Here is the method to solved this problems,that is you only need to copy the file of lic_key_2.dat and rename it to lic_key_2.x4711 .
Look like this:
Then set up to properties of the file with Read-only.
Then,reactivate it again,that the problem gone.