What do you expect to fix?

The demo server allows you to start your own Funeral Quest server, with limitations of a maximum of six players total, 2 players online at once, and it will not be advertised on RTSoft's Server List.

So, if you and a few friends wanted to play FQ, the demo server allows you to try it out.

Just click on 'New Player' on the login screen, and it should allow you to create a new player and test it out and so on.

The server isn't required to play FQ on other servers... it is only needed if you want to start your own. If you want to increase the number of players and so on, you have to buy a 6 month license from RTSoft, which then allows you to have something like 150 (or maybe 200) players max, 6 players on at once, and it will be advertised on the RTSoft Server List if you so choose.