I logged in into my ISPConfig-page and I added a client and a website. Then I logged out. Half an hour later, I logged in again and now my ISPConfig website replies: ERROR 101: Wrong username or password. What is going wrong?
Are you sure you used the correct username and password and didn't mix up ISPConfig users and system users?
Yes, I am sure, I am using the admin/admin combination... (this is the one and only user in the system).
Please check if your ISPConfig mysql database is still there with e.g. phpmyadmin. You can set a new admin password with the mysql md5 function, the database table is sys_user. You shall change the ISPConfig admin password right after the first login!