Hello, I have the problem that I as a GM can only delete characters that are not members of a guild via the character overview in the livemap. When I tried to delete a character that is in a guild, I got the message that the character could not be deleted.

At least it would be nice if there was at least one message why it cannot be deleted.

Maybe someone can help me solve the problem.

You should be able to delete all characters except guild leaders.

Where exactly can I set that? I have not found this setting yet.

What setting? There's no setting.
If you would delete a guild leader character, there would be a leaderless guild. The server doesn't even start up with a leaderless guild in the database, hence the protection against deletion of guild leaders.

Is there a way to delete these characters? in my overview I now have 20 characters from people who no longer play, I would like to remove them.

The only way I know of, edit the `characters` table in the database, assign your own AccountID to all the characters you want to delete. Then you can login to the game with their character and disband their guild.

That could take some time for 20 chars though.

You can also use the procedures in the database:
fb_destroyGuild
p_deleteCharacter
p_deleteGuild