Hi aheben,
Thank you for your help.
However, I moved the model and I have the same result :-/
NB : The "slicing failed with an unexpected error" does not occur if I try to slice on another printer. For example, I tried the FLSUN Super Racer and it works well.
I tried to change the configuration of the extruder but I don't knwo what to change. I saw I have a Nozzle Size to empty on the top bar but I don't knwo where to configure it (there is not such parameter in the Printer or V400 Hotend menus).
I must have forgetten something but I don't know what.