Reconciling checking account.

@bhall726 It's hard to know what you're overlooking because we can't see your data or what you're doing. Let's take a stab at how to proceed...

So you pulled your transaction history into Quicken, correct?
Is this just one bank account, or multiple different accounts? 
Is the account balance correct in the register?
Can you still open your data in Banktivity, so you can compare it against Quicken? 


I'd start with one bank account. Go back to the beginning of time and look to see if there's and opening balance or adjustment there which could be throwing things off.

The next step would be to see if you can find a time when the balance is correct, and which you can reconcile correctly. Go back to the end of the first year your have transactions for this account. If you can compare with Banktivity, is the balance on 12/31 of that years the same in both programs? Now try to reconcile up to that date (e.g. just the first year's transactions). In the reconcile window, enter the 12/31 date, the balance at the end of the year, and then click on Select All transactions. Is the reconcile balance zero? If so, complete the reconciliation. Jump forward one year and do the same thing again. If you have a lot of years, you can try this jumping 2 or 5 years ahead. The goal is to see if everything reconciles up to a certain point in time but then breaks.