Check brd_type px4io start failed

I bought 16 dropix for a project. After updating firmware i get this error “check brd_type px4io start failed” in 13 of this boards. Only 3 works after updating.
All 16 boards have same firmware (3.7.5), same SD. I tries install and old version 3.5.2 but i get the same error.

What should I do in this case?

I have the same problem with at least 2 boards…

Dropix V2.1
bought: 12.7.18
Mission Planner: 1.3.58
Copter Version 3.5.7 or Plane 3.9.1 (no ChibiOS)
new SD-Cards
never plugged in any kind of Hardware to the second one

Please contact us here please

Contact with Drotek after sale service, they solved my problem very quickly.

We’re having the exact same problem, how did you solve it?