hi guys im new on this forum but have been lurking around for around a month. Recently I purchased a used smok xcube 2 but it was stupid of me to not check on the spot as batteries were not provided. After placing the batteries in, I realised that the display wrote 'error: no secret-key' . I went to look up google and found out that it could be a firmware upgrade problem and taking out the batteries and putting them in again would be fine. However, it wasnt the case. Need some help over here.