file 4 cannot be read at this time

ORA-00604: error occurred at recursive SQL level 1
ORA-00376: file 4 cannot be read at this time
ORA-01110: data file 4: '+DATA/orcldb/datafile/undotbs2.343.817729081'

Startup nomount

select status, file# from v$datafile where status='recover';

status     file#
-------     ------
recover     4

set autorecovery on
recover datafile 4
alter database datafile 4 online;


shutdown immediate

lsnrctl stop

startup

lsnrctl start