You need to check the status of the journal, if it is not posted then there will not be a Folio Number, Period or Dated Value showing.
If the journal is Closed but not posted, to correct:-
On the Journal Header Right Click and Select Modify Record.
Right Click again and Select Open.
You will then receive message Re-open this Nominal Journal Template select Yes.
Check that all of the fields, value and dates are entered correctly and Apply to save.
Right Click and then select Post, make sure that you enter the correct journal date.
The Lasted Posted Section will then update with the Folio Number , Period and Dated.