Possible solution! (Independence)
For incorreect SIM or not activated SIM message.
I just found out (after hours of trying every unlock method) the following issues:
-Independence 1.2.1 works correctly with the provided AT&T SIM card (all fine)
-Independence canīt really activate my own SIM card from O2 Germany
-after every successful activation of AT&T my iPhone vibrates shortly
-the O2 SIM does this NOT after Independence says itīs activated.
So maybe the programmers of Independence may take a closer look at this issue and maybe they can help out.
My iPhone can still not be used as an phone.