Thread:Project:Support desk/Login & Password Authentication issue after upgrade/reply

I guess that you somehow use passwords, which are in the wrong password format.

Do you use any extensions, which change something with the passwords?

Any specialties for login? LDAP or something?

Finally, please look into the database table user and check the column user_password. This column will contain a password hash. Check it for one user, where it is working again and for one user, where it is broken. What are the first like 5 signs in the according fields? Are they different?