Can't create character (Error code 316003)

Hello !

I “installed” the PTR using the copy-paste method from my live instance (I’m on a slow DSL connection), it seemed to have updated fine ( but I can’t create any character (seasonal or not) once the game is launched :
(Launching the game gets me directly to that character creation screen, I can’t copy my live profile yet.)

I tried to reboot my computer, scan & repair with the launcher in administrator mode but it didn’t changed anything.
In-game version looks fine : and my live instance (v2.7.1.77744) is working fine.

Am I missing something very obvious or is this a bug ? Should I uninstall the PTR instance and do a clean download / installation ? I don’t remember copying the files and updating being a problem in the past =[
The launcher is installed on my main Windows SSD and the games instances are on a separate NVMe drive if that could be a problem.

D3Debug file : (Launched the PTR, tried to create a new hero, got the error message and exited.)

Thanks in advance !