Can’t login to the admin panel AND import is blocked

Dear support team,

This week, I found myself locked out from my customers’ website. The website itself works fine, but I can’t login to the admin panel. I saw another post with the same issue, but the solution doesn’t work for me, as I do not have this setting.

I can login if I disable the AIOS plugin via FTP. However, as soon as I enable it again, I am locked out again.

So, my idea was to overwrite the page with the latest backup. To be sure it works properly, I tried on a subdomain. I am using the All-in-One WP Migration plugin for export/import (since years). But this time, it doesn’t work. The import is pending and doesn’t finish – without any error message. It works if I disable or delete AIOS. This is what I found out with the help of All-in-One WP Migration support.

Usually, I’d try to provide you with a better analysis. But meanwhile, I’ve tried so many things that I even don’t remember what I did. I’ve disabled most of the security settings, tried again, disabled the plugin, tried again, and so on. But the end of the story is still:

I can’t enable the plugin without being locked out, and I can’t import my backup, because it keeps pending.

I appreciate all kinds of hints which could help me. Thank you in advance!
Katrin

The page I need help with: [log in to see the link]