Validation rule triggered even with wrong status

Question

When the status is "Completed" or "Complete" no one should be able to edit a record.

I wrote the following validation rule:

AND(OR( AND( NOT(ISCHANGED(Status)),
OR( ISPICKVAL(Status, 'Complete'), 
 ISPICKVAL(Status, 'Completed') ) ), 
 AND( ISCHANGED(Status),
OR( ISPICKVAL(PRIORVALUE(Status), 'Complete'), 
 ISPICKVAL(PRIORVALUE(Status), 'Completed')))))

But the above rule throws an error even when I'm changing the status picklist to a value other than "Completed" or "Complete".

Answer 1

You can try like below, when old status is either Complete or Completed, it will not allow you to update the record -

AND( 
  OR( 
    ISPICKVAL( PRIORVALUE(Status), 'Complete'), 
    ISPICKVAL( PRIORVALUE(Status), 'Completed') 
  ), 
  NOT( ISNEW() ) 
)