ORA-01173: data dictionary indicates missing data file from system tablespace

admin

ORA-01173: data dictionary indicates missing data file from system tablespace
Cause: Either the database has been recovered to a point in time in the future of
the control file or a datafile from the system tablespace was omitted from the
create control file command previously issued.

Action: For the former problem you need to recover the database from a more
recent control file.For the latter problem, simply recreate the control file checking
to be sure that you include all the datafiles in the system tablespace.