Vanguard OL-301A error again

@ramatuska Please see the step by step procedure for reconnecting your accounts to Vanguard posted as the 4th item under "Best answers" on Page 1 of this discussion:

If you have not followed this procedure exactly, please try it and let us know if it resolves your problem.

@as_hiker Are the accounts that are not downloading ones that have been connected to Vanguard since before 2009, when they converted to their current in-house brokerage platform? If so, you may need to use Vanguard's old "Pershing" account numbers, which begin with two digits and a letter, like 40V, to reconnect. Please follow the following steps exactly, paying special attention to Step 4.

Some of these steps may not be necessary in every case, but I want to cover as many bases as possible.

1. Back up your data file in case something goes wrong.
2. Go to Edit > Preferences > Investments and make sure the "Default to Simple investing for new accounts" box is not checked.
3. Go to Edit > Preferences > Downloaded transactions and un-check the "Automatically add to investment transaction lists" box if it is not already un-checked. This will give you a chance to review any new transactions to make sure there are no duplicates and the transactions are going to the correct accounts.
4. Go to each problem account, click on the gear at the top right and select Edit account details. Make a note of the account name and the Vanguard account number.
   For accounts that have been connected since before 2009, when Vanguard converted to their current brokerage platform, you may need to use old account numbers that begin with 2 digits and a V rather than the current 8 digit numbers when re-linking the accounts. If you downloaded transactions using Web Connect (QFX) during the outage, your account numbers may have been changed to the new numbers. If in doubt, open a backup from before the outage, record the correct account numbers, and then return to your working file. You are only using the backup to see what account numbers Quicken was using for Direct Connect before the outage. 
5. Now for each problem account, click on the gear at the top right, select Edit account details, and then the Online Services tab. If it says the account is set up for transaction download, click on Deactivate. Do not click on “Set up now” after deactivating, you must go through the following steps.
6. Go to the General tab and now you should be able to select Complete mode. Select that.
7. At the top of the Accounts bar, usually on the left side of your screen, where all of your accounts are listed, click on the plus sign. This should open the Add account window. Don't worry, you will not be adding any accounts, you will be linking your current Vanguard accounts in Quicken to the corresponding online accounts.
8. Enter Vanguard and you should see the Vanguard logo on the right. 
9. Below the logo, click on Advanced options. Read the permission screen about Quicken and Intuit and click on Continue.
10. Under How should Quicken connect, select Direct Connect. Click on Next.
11. Provide your Vanguard username and password, and check the Save to Password Vault if that is how you normally operate. Click on Next.
12. You will see a list of all your Vanguard accounts. Any accounts that are already connected will be marked Don't add to Quicken. Accounts that you can connect will have entry boxes. For your existing problem accounts DO NOT SELECT THE DEFAULT OF ADD TO QUICKEN. Instead, select Link to existing account and select the Quicken account to use. Do not guess here. If you don't know which account to select or there are Vanguard accounts that you don't want to track, select Don't add to Quicken and only do the accounts you are sure of. You can pick up at step 7 later and reconnect any other accounts later if necessary.
13. Click on Cancel if you are confused at this point and your accounts will not be re-linked. If you are satisfied, click on Done and your accounts should be set.
14. Check to make sure any downloaded transactions are going to the correct accounts.

If you have attempted to update while the accounts were in Simple mode, you may see Added or Removed transactions during that time. You will need to delete these. If there are problems, restore the backup file you saved and you will be back to where you started.