I have found some language file issues in RC1 which make it impossible to translate some expressions and words.
1) Registry Cleaner
"Engine settings" tab: "List MRU and other history data" option.
That expression cannot be translated simply because it is NOT in the English.lng language file!
2) Help > Live Support
Live Support Status = (unknown)
That word (unknown) is NOT translated.
I don't know why...
Yet there's such a word in the English.lng file under , 33 and I have translated it!
Those issues should be fixed, please...