The New York Stock Exchange on Monday morning said it resolved a technical problem that resulted in the halt of trading in stocks of several high-profile companies, including Class A shares of Warren Buffett’s Berkshire Hathaway Inc. The shares resumed trading before midday Monday after a lengthy trading halt that appeared to show them changing hands for as low as $185.10, a drop of 99.97%. Experts said any trades actually executed at that level would almost certainly be invalidated....