[CLIENT] - unknown error - Friends with special characters

When a Friend with a unique summoner name with a special character, such as ø, is on at the same time. Their summoner name does not appear correctly on the friends list. The game client produces an unknown error. Re-adding the summoner does not fix the problem. The error occurs quite often whilst they are online. Other friends who have added the unique summoner name may not experience the same error, so re-production will be hard.