After trying to do it firmware refresh with DJI Assistant 2 i got the message "Update failed - Error Code: 0x028103" and then I had to send it to DJI Repair Center what caused the cost of 280€ (Aircraft Main Bord 153€+Repair Service Fee 50€ + Freight 30€ + Tax).

Hi there sorry read about the troubles you had recently. I was able to pull up the case using your Forum account. I will escalate this to a higher level of management for us to check and see if there's anything that we might help you with regards to your case. Anticipating your patience. Thank you.

i'm sorry, did you try to tell them it was DJI assistant?

Yes i do. It is true that I had a collision but everything worked except front left LED,  the dron worked normal. I found advice here (DJI Forum) to traying with firmaware refresh to solve the problem with LED and
then it happened. I would normally should pay for ESC Board,Repair Service Fee,Freight but not for Aircraft Main Bord (185€). Thats is my opinion!

Never had a problem with updating with Assistant 2.

DJI Assistant 2 has always worked fine for me, much better than trying to update the aircraft with DJI Go.

Search for "dji assistant update failed" on google and you will see how many people have same problem like me.

Sorry to read. Which part was damaged by the fimware update?

Main Board.