The New York State attorney general’s office filed a civil lawsuit on Saturday accusing Trump University, Donald J. Trump’s for-profit investment school, of engaging in illegal business practices. The lawsuit, which seeks restitution of at least $40 million, accused Mr. Trump, the Trump Organization and others involved with the school of running it as an unlicensed educational institution from 2005 to 2011 and making false claims about its classes in what was described as “an elaborate bait-and-switch.” In a statement, Eric T. Schneiderman, the attorney general, said Mr. Trump appeared in advertisements for the school making “false promises” to persuade...