yes, TRUSTED_PROXIES is set TRUSTED_PROXIES=192.168.250.250
Also changing the fees does not help for the 500 error. Neighter with all fields set to some values, nor after rewinding the changes.
I can’t get paypal express module to work. Also: As said, I can not even view the invoice in the client panel… Isn’t it the case, that at this point the payment processor is not even known yet?
Unfortunately the “System log” tab is still empty so I can not provide you with any useful data.