Hi!

At Database connection window (for first start):

- did you select "Save data to local machine" ? If so it should be: address localhost (or 127.0.0.1), port 64000, user cqrlog password cqrlog (showing dots).

- if you did not select it: It should be localhost (or any other mysql server's ip in network), port 3306, user and password what you have initiated at mysql you are going to use server.
If you try that here is a copy of my other message to explain what to do:

Open console and give:
sudo mysql

If your mysql-server is properly installed and running you should get prompt:

saku@NanoPi-Neo:~$ sudo mysql
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 38
Server version: 10.0.36-MariaDB-0ubuntu0.16.04.1 Ubuntu 16.04

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]>

Then write line:
GRANT ALL PRIVILEGES ON *.* TO 'cqrlog'@'%' IDENTIFIED BY 'cqrlog';

You will get response like:
Query OK, 0 rows affected (0.04 sec)

Then type:
quit

Go back to cqrlog "Database connection" window. Keep address 127.0.0.1 (or "localhost") but change port from 64000 to 3306.
username is cqrlog and password is cqrlog.
uncheck "Save log data to local machine"

If this is first run wait a while when cqrlog creates first empty log. On second run (and after that) you should see a list of logs available.
Then just select log and press "Open log"

I have found out that sometimes things work better if you do not check "Save data to local machine" and do the steps above to use mysql server running at port 3306 on local, or any networked machine.