There is a few reason why a robot would start after an upgrade.
- If you needed to use the St-link for the upgrade, do not forget to charge the Binaries file on the Log SD card. This file will finish the installation of the upgrade. Once it's done, you won't need the ST-Link for the next update, all will be done only though the SD card
- Check if you have a SD card in the Log slot of the drone. You won't be able to arm the drone without it.
- Check the battery, for safety measure, if your battery is cold or damaged you won't be able to arm the drone.