Errors
in file /apps/app/oracle/admin/apcell1/udump/apcell1_ora_5850.trc:
,
[], []0: internal error code, arguments: [kcratr1_lostwrt], [], [], [], [], []
ORA-600
signalled during: ALTER DATABASE OPEN...
Solution
$sqlplus "/as sysdba"
SQL>STARTUP
MOUNT;
SQL>RECOVER
DATABASE;