Internal Error 1000 when trying to create a contact via the API and an Oauth2 connection

Internal Error 1000 when trying to create a contact via the API and an Oauth2 connection

Hi, I'm trying to create a new contact using the API and an Oauth2 connection !
The connection is working and I can list my invoice and contact with no problem.
But when I try to create a new conntact I get a Internal Error 1000.

Any Idea on how to fix that ?