Azure SQL Server export via sqlpackage produces Error SQL71501 (Unresolved reference to object MS SyncAccount
This occurs when Azure SQL Data Sync was used on the database to sync with another database. The remnants from the DSS schema used by SQL Data Sync do not allow to export the database due to inconsistencies.
In order to successfully export the database, we need to:

Create a database copy. You can check how to create a copy of the
database using the portal at the portal. (there is also
documentation for doing this using T-SQL or PowerShel.

Remove the Data Sync metadata objects from the copy. You can find a
script to do it here ... Please make sure you are connected to
the copy.

Export the database from the copy.

Delete the database copy.


For more information, visit this article.