Originally Posted by gromada
When I came to the point:
MySQL is indeed using 3306 port. It is a default port and it's been in use for other databases.
Maybe I misunderstood, but are you trying to use this guide to install KnowledgeTree on a server that already has MySQL installed? If so, it won't work as the stack installer contains its own instance of MySQL.
Try the following command to see if your server reports MySQL already running.
netstat -tlnp | grep 3306
If it is, you will probably see output like this:
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 4514/mysqld