Hi, I'm Robert and I'll be helping you with your financial software question.
If you are using the essentials version on the mac, that is a known problem
You need to sort the register by date to get the running balance to appear.
There is a title bar above the columns that says what is in the column below it. If you click on that title bar right where it has the actual word "Date" it will sort by date and the balance column will re appear.
That is a new "feature" on the essentials version
What happens is that if the register is not sorted in date order the running balance will of course not match the statement that you get from your bank. A lot of people were complaining that it was doing something wrong. Rather than try to explain this to thousands of people quicken decided to just blank out the balance column when its not sorted in date order.