Error when dropping tablespace:
ERROR at line 1:
ORA-01122: database file 6 failed verification check
ORA-01110: data file 6: '/data/oracle/oradata/xe/admindb01.dbf'
ORA-01203: wrong incarnation of this file – wrong creation SCN
Solution: take the datafile offline before dropping it:
alter database datafile '/data/oracle/oradata/xe/admindb01.dbf' offline drop;