If you don't have Credit Invoices enabled, then yes, you can still re-open a failed Manual invoice. However, if you do have Credit Invoices turned on, then you will no longer be able to re-open failed invoices.
If you don't have Credit Invoices enabled, then yes, you can still re-open a failed Manual invoice. However, if you do have Credit Invoices turned on, then you will no longer be able to re-open failed invoices.