CTRL-F7 is indeed the keys to add additional characters to your scene and does work.
Are you possibly using a keyboard that has dual functionality for the F1-F12 keys. For this type of keyboard you would normally have to press a certain key to switch between using the function keys or for using the keys for office applications etc.
I would consult your computer keyboard instructions if you think this may be the case.
Peter EdwardsForum Moderator
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