To all new V2 users.
By accident I had introduced a bug in firmware 521 which was up on the server both as beta and release version for a short time. If you have version 521 please update to version 522 or downgrade to 515. This bug only affects some Bullets which has a new design of the control PCB.
Symptoms include crashing of the bullet and a black screen at startup.
If your bullet will not start up, please contact Aillio to receive the guide of how to do the recovery procedure.
Sorry about this mess.
Happy roasting.