The CNBC News item SpaceX, Boeing design risks threaten new delays for US space program says:
Just ahead of the first scheduled un-manned test flight slated for March 2 under NASA's multibillion-dollar Commercial Crew Program, NASA's safety advisory panel cited four "key risk items" in its 2018 annual report earlier this month.
For Boeing, they include the capsule's structural vulnerability when the heat shield is deployed. For SpaceX, the report mentioned the redesign of a SpaceX rocket canister following a 2016 explosion and its "load and go" process of fueling the rocket with the crew already inside the capsule. "Parachute performance" remained an issue for both companies.
Question: What is SpaceX's "rocket canister"? What exactly was it that was redesigned?