Apple stock (NASDAQ: AAPL) fell in after hours trading Thursday, according to The Street, falling .4% to $128.16. The dip came after an announcement about a defect in the tech giant's highly anticipated Apple Watch. According to reports, the wearable's tactic engine made by AAC Technologies, or the part of the watch responsible for the tapping sensation users feel when they receive notifications, has been prone to issues. Another company, Nidec, also produces the engines for Apple, however, is not experiencing the same problems.