Migration CRM 2015 to 2016 inplace

Hi,

I'm trying to perform a migration 2015 to 2016 inplace. But it failed each time with this message :

I found a topic about that (https://community.dynamics.com/crm/f/117/t/194884) but installing language pack doesn't change anything.

I didn't find that GUID in my AD users. I fount it in the OrganizationBase table, it's the SystemUserID. Have you already met that problem?

Thank you,

Fabiien