What is this message all about?

Your score won't be stored in Database because the Arcade only saves users top score per Game.

What does it actually mean? It's going to confuse readers. And the grammar is poor.

Also the message shown to guests is currently

The administrator has disabled playing games for your usergroup

I want to change this to

Sorry but you must be a member of the AV Forums to play in the arcade.

I've looked in the phrases for the above text but can't find it. Where do I change it please?