Hi @Kebede, Kirubel ,
If the reports are based on stored procedures, you might try specifically allowing those users execute permissions on the stored procedures.
GRANT EXECUTE ON spName TO ReportingGroup;
As you mentioned, you have migrated a few SSRS reports from SQL 2012 to SQL 2016.
If you move a report server database to a new or different SQL Server Database Engine, you must re-create the RSExecRole in the Master and MSDB system databases.
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