Good afternoon,  About the Drone:  I just purchased a DJI mavic 2 pro drone, when trying to connect to the DJI GO 4 app I got this error message:
"Activation Falled - Activation falled, server error (-2), please retry. If it still fails after retry, please contact DJI Support. " (Print attached).
This error occurs at the stage when the application tries to synchronize the drone's CN with my account email already logged in.
I had no problems connecting the drone to the controller, just as the drone was promptly identified and updated by the application.

Show this error in IOS

The error message seems to indicate the registration server is not connecting. Two things I'd do:
1. Try connecting from a different WiFi router
2. If #1 fails, try connecting later

Or use another device. DJI drones seem to activate better with iPhones.
On a separate note I wouldn't display my private email address on here if I were you...

I spent a long time trying to do that. I used different devices, I used the two internet networks in my house and it didn't work.

After contacting DJI Brasil and reporting the error that appeared on the iphone, they replied that SN is banned.

Now I'm trying to return the product.

You bought it brand new and the serial was banned?

Sadly yes. I bought it from an amazon partner seller. I'm wating for a response to the reason for the ban