KUALA LUMPUR, Malaysia—The most comprehensive official report into Malaysia Airlines Flight 370 revealed no new leads into what caused the jet’s disappearance, compounding public frustrations over the fruitless search for wreckage in the southern Indian Ocean.

The 584-page report comes on the anniversary of the disappearance of the Boeing 777, which vanished from radar after taking off from Kuala Lumpur on March 8, 2014, with 239 people on board. It was the third progress report released by international teams of experts,...