Blogger Engineering ended support based on unresolvable technical issues - and not without considerable deliberation.
For a number of technical and operational reasons, we’ve decided to finally end our support for migrating legacy accounts and blogs after December 5, 2011.There were many technical details involved with "legacy" account migration, which prevented a more aggressive migration strategy.
Blogger Engineering having gone with a more permissive migration (migrate when you feel the need), this leaves a few Blogger "legacy" account owners unable to migrate.
The longer people leave their "legacy" accounts unmigrated, the more account owners will forget login details.
Trying to migrate a "legacy" account, when the account name and / or password is not known, is going to present a problem.
- Legacy account migration starts with a valid account name and password.
- Legacy account migration requires a valid Google account.
- Account / blog recovery only works with Blogger / Google accounts.
Legacy account migration starts with a valid account name and password.
The legacy account migration process starts with the account name and password. This is an essential, and intentional requirement.
If you are not the blog owner, you can't migrate the account. If you don't know the account name and password, you can't prove that you are the account owner.
Only accounts that need to be migrated can be migrated. If the Blogger account has already been migrated - or simply does not need migration - the owner may or may not receive appropriate advice.
Legacy account migration requires a valid Google account.
The purpose of migration is to associate any owned blogs with a current Google account. If you don't have a Google account, you setup a Blogger / Google account, when you migrate.
Account / blog recovery only works with Blogger / Google accounts.
The "backup" email address, for an account recovery, is most reliable when used with a Blogger / Google account.
A Blogger / Google account starts with an account name that is predictably based on an email address - though the email address may, or may not, exist.
A Legacy account allowed use of any desired account name - and may or may not have used a genuine backup email address. Some Blogger account owners may have even used a bogus email address, intentionally.
If you have a "legacy" Blogger account, the recovery process will try a GMail account, possibly based on the "account name" that you use. If you are not the owner of that GMail account, you can't receive the recovery email, and you can't recover account access.
The bottom line is bleak.
You may be unable to recover account access. If the blog is so old and owned by a legacy account, it may be unrecoverable.
You may have to let this one go. If you're trying to re use the blog, you may have to make a new blog, and merge the two blogs. If you're trying to delete the blog, that may simply not be possible.