it just says connection failed error code 0:66003s:4688822960:0b

Hey 789100yousef​ 

I’ve seen this particular connection error reported before.

If you're on PC, try disconnecting any non-essential USB devices before launching Battlefield 6. In particular, unplug devices like external drives, USB sticks, SD card readers, and USB docks/hubs. Leave just your keyboard and mouse connected if possible, then try launching the game again.

It doesn't sound like a connection error, but this has resolved the same 0:6600... error for a number of players.