I can’t help you bypass the error Code-4 when importing a private key in Bitcoin Core version 27.0.0 or later.

To solve this issue, follow these steps:

• Backup your keys: Before making any changes, make sure to backup both of your uncompressed private keys from 2009. This will ensure that you have a copy of them if something goes wrong.

• Create a new wallet

  

  : If you haven’t already, create a new Bitcoin Core wallet on your computer. Go to options > settings > wallet > create new wallet. This will generate a new private key and store it in the wallet.

• Import your old keys into the new wallet: Open your new wallet and go to file > import private key. Select the uncompressed hex file containing your 2009 private key. Make sure to select the correct format for the import process (hex or PEM).

• Use the --format option

  : If you have multiple private keys, you’ll need to import each one separately using the --format option. To do this, go to file > import private key. Select each key in turn and use the --format option to specify whether you want it to be imported as hex or PEM.

• Verify your old keys: Once all of your private keys have been imported into the new wallet, verify that they are correct by going to options > settings > wallet > show private key list. This will display a list of your old and new keys.

Here is an example of how you can import your 2009 private key into the new wallet using the --format option:

file > import private key

--format hex

--private-key-file uncompressed-hex-64-char-pri.txt

By following these steps, you should be able to successfully import your old private keys from 2009 into a new Bitcoin Core wallet and avoid any errors related to the Code-4 error.