Missing string

htdocs/lang/en.utf8/group.php

@@ -246,6 +246,7 @@ $string['sendfriendshiprequest'] = 'Send %s a friendship request';
 $string['cantdenyrequest'] = 'That is not a valid friendship request';
 $string['cantrequestfrienship'] = 'You cannot request frienship from this user';
 $string['cantmessageuser'] = 'You cannot send this user a message';
+$string['cantviewmessage'] = 'You cannot view this message';
 $string['requestedfriendship'] = 'requested friendship';
 $string['notinanygroups'] = 'Not in any groups';
 $string['addusertogroup'] = 'Add to ';