ORA-00979: not a GROUP BY expression

Hi team,

Do you have an idea why following query is working fine on 12.1.0.2.0 with compatible =11.2.0.4.0  but failing on 12.2.0.1.0 with compatible = 12.1.0.2.0?

Is there a way to refine the query to work for compatible = 12.1.0.2.0?

thank You

select

'??:97A::SAFE//' || t1.SUB_ACCOUNT_97A AS SUBSAFE_ACCOUNT_97A,

'??:17B::ACTI//' || 'Y' as ACT_17B,

cursor ( select

'??:35B:' || t2.SEC_ID_35B AS INSTRUMNET_ID_35B,

'??' || t2.SEC_NAME_35B AS INSTRUMNET_NAME_35B,

t2.SEC_SUB_ID,

'??:90B::MRKT//ACTU/' || t2.CLOSING_PRICE_90B_C AS MRKT_ACTU_90B,

'??:98A::PRIC//' || t2.PRICE_DATE_90B AS PRIC_DATE_90B,