You should go down till the line 'en_GB.UTF-8 UTF-8' and select it by pressing the 'Space' key. An asterisk then appears within brackets preceding the choice (it is possible that the line is already selected. In this case, keep it selected, i.e. with an asterisk displayed within brackets).
Vous avez entré un nom de page invalide, avec un ou plusieurs caractères suivants :
< > @ ~ : * € £ ` + = / \ | [ ] { } ; ? #
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