After we upgraded Umbraco from 7 to 11.1, users can't seem to log in with their passwords and they need to reset them. While checking password on logon, Umbraco logs following error for some members "Unable to determine member password hashing algorithm", and it returns negative result. Is there any way I could catch this error so I could automatically send them mail for resetting password? Or way to make these old passwords work again maybe? I'm open to suggestions if you have any. Thanks

The hashing algorithm for passwords changed in I think v8, so it required all users to get new passwords. You should assume no passwords are ok, and just send mails to all of them?

I've just filtered members to test something, there're lot of them that havent touched their accounts for quite some time, but when testing their mail with login, it doesn't seem to give me error. That's why I'm hesitant to just send them to everyone

In that case I'd have a look in the cmsMember database table to see if the hashing algorithm is an old one / missing on some of them

is there a way to tell? I tried using details from member that has the issue but passwordConfig seems to be the same across the board. Comparing securityStampToken I saw that old one was made from Guid but that doesn't seem to indicate much. And last probably biggest difference I noticed was that actual hash itself was like 3rd of the size of the other hashes