First i'm hearing of anyone having this issue (For a measure of those it affected)

I'd contact yahoo support, see what they can do. May have been better to action upon this while xtramail was still on yahoo's platform however.

I can't contact yahoo support because they require a valid email address ... and ... my email address is not valid!

Hmm ...

ok just found a possible solution using this form bit.ly/2l14F4Q

Got around it by following the emailed out instructions. 

Re-associated with a non xtra email before the platform migration was completed.

yitz: Contact Yahoo Support and they can link it to another non-xtra.co.nz Yahoo ID. https://help.yahoo.com/kb/SLN26180.html

I've just run into this as well, contacted Yahoo support and they've told me "the login info connected to it has been deleted. This means that while there's no way to help you get back in, I can delete it for you."

I am deeply unimpressed, as I've had that Flickr account since long before the Xtra tie-in happened. It still emails me on the original email address when someone interacts with a photo.

I don't know if you guys were spam binned or otherwise, but I received multiple links and emails stating what would happen leading up to it included in the agree to migrate messages about the yahoo services incl flickr if not re-associated beforehand.

One of the sites is still active.

https://www.spark.co.nz/emailchanges 

Which changed from

What happens to my Flickr account?

Early next year, your @xtra.co.nz will no longer log you in to your Flickr account. If you want to keep using Flickr, you'll need to create a new free Yahoo ID then visit the transfer page to move your Flickr account to the new Yahoo Identity. It's a good idea to do this now.

If you have some photos on Flickr but don't regularly use it, now's also a good time to download any photos you want to keep.

to 

 

What about my Flickr account?

 

Now that you're switched over, your @xtra.co.nz email address will no longer log you in to your Flickr account. If you want to keep using Flickr, you'll need to create a new Yahoo ID.

Oblivian:

 

I don't know if you guys were spam binned or otherwise, but I received multiple links and emails stating what would happen leading up to it included in the agree to migrate messages about the yahoo services incl flickr if not re-associated beforehand.

 

OK, I don't remember seeing that message. I never used my Xtra email address as an email address though, so from my perspective there was nothing to migrate. I've had a look through my email (which goes back to 2003 and has all my original Flickr account creation stuff in it) and can't see anything about migrating Flickr at the time of the Xtra/Yahoo split.

Luckily for me it's about time I dropped flickr and 500px - deleted everything.

Please let us know if you find a way to link it to another account. it must be possible since you can still see the photos there under the "account" that can not be accessed. yeah right. maybe need to escalate it.

Main email and 2 aliases on March 23rd..

Chances are, if you didn't go through the agree to migrate session?, it was probably dispatched with.