Net core 3.1 Post Sis Imports Error: 500

[Alexandre_Sch]

Hi Community! 

I have a 3.1 net core Lti app already working with Canvas. I can get/post users, enrollments and etc. 

Now, i'm trying to automate my Sis routine and, for that, i'm using the Sis Imports Post API

/api/v1/accounts/:account_id/sis_imports

I received the file from a form: 

And i'm receiving a statusCode 500: Internal Server Error. 

What am i missing? 

my csv file is:

Regards,

ALexandre S.