can't add Principal IRA Account

First, deactivate all the accounts with the affected financial institution

1. Open Quicken.
2. Go to the Accounts menu and choose Hide and Show Accounts;
3. Uncheck any accounts with this specific financial institution (FI) that are hidden in Lists;
4. When complete, click the Settings button in the bottom right of the register for the affected account;
5. Click on the Downloads tab.
6. Click on Disconnect Account, then click Done. Do this on each account with this FI. 
7. Quit Quicken.

Second, delete Quicken passwords from the Keychain

1. Open Finder and go to Applications > Utilities > Keychain Access app;
2. On the left panel in the Keychain app, set the Keychains to Login and the Category to Passwords.
3. Find and delete any entries that show Quicken or Quicken Connect and this FI name;
4. Quit the Keychain Access app and open Quicken.

Third, update the bank list in Quicken and reconnect accounts

If there are multiple affected accounts

1. Go to Accounts > New and pick an account type matching one of the affected accounts.
2. At the bottom of the window that lists the financial institutions, click the "My bank is not listed" question mark icon; then click Update List.
3. When the list finishes updating, it will display the current date. Click the Show List button to continue.
4. Type the name of the financial institution and make the appropriate selection.
5. Enter your login credentials and click Continue.
6. When Quicken has returned all accounts discovered for this FI: In the Action column, make sure that the accounts are set to LINK to the corresponding accounts in Quicken (rather than Add or Ignore).  

If there is a single affected account

1. Select the affected account in the account sidebar.
2. Go to Settings > Downloads tab and select Connect Account.
3. At the bottom of the window that lists the financial institutions, click the "My bank is not in the list" question mark icon; then click Update List.
4. Type the name of the financial institution and make the appropriate selection.
5. Enter your login credentials and click Continue.
6. When Quicken has returned all accounts discovered for this FI, make sure the corresponding account is showing LINK in the action column and all other accounts are showing Ignore.