SpaceX Delays Test Firings Written 3 April 2019

CNET News reports that “early Tuesday morning, Elon Musk said on Twitter that the first test of a Raptor engine as part of Starship had been set back by ‘some challenges with ice formation in the cryogenic propellant prevalves. Hopefully overcome soon.’” SpaceX’s Falcon Heavy rocket’s test firing also was delayed, but the rocket “is still slated for its first commercial launch on Sunday evening when it carries commercial communications satellite Arabsat 6A to orbit.” 
More Info (CNET News)