Find the enabled events using ORADEBUG EVENTDUMP and disable it

+ASM1 AS SYSDBA> oradebug setmypid
Statement processed.
+ASM1 AS SYSDBA> oradebug eventdump system
27090 trace name errorstack level 3

+ASM1 AS SYSDBA> alter system set events '27090 trace name errorstack off';
System altered.
+ASM1 AS SYSDBA> oradebug setmypid
Statement processed.
+ASM1 AS SYSDBA> oradebug eventdump system;
Statement processed