Error codeunit not found while converting 2013 database in nav 2017

Hello everyone,
i am currently upgrading data from nav 2013 to nav 2017.

I get this error while opening the 2013 database on nav 2017 (which contains only tables) that block me from converting :
Codeunit 33000250 does not exist.

this codeunit is not called in any table code ( i verfied by exporting the tables and searching for it).
can someone help me to pass this error?